Genetic markers for predicting responsiveness to fgf-18 compound

ABSTRACT

This application is directed to the use of biomarkers for predicting the sensitivity to treatment with an FGF-18 compound of a patient having a cartilage disorder, such as osteoarthritis, cartilage injury, fractures affecting joint cartilage or surgical procedures with impact on joint cartilage (e.g., microfracture), in order to reduce the risk of adverse events and increase the overall benefit after therapy.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. application Ser. No. 14/420,076, filed Feb. 6, 2015, which is the U.S. national stage application of International Patent Application No. PCT/EP2013/066421, filed Aug. 5, 2013, which claims the benefit of U.S. Provisional Patent Application Nos. 61/680,480, filed Aug. 7, 2012 and 61/778,912, filed Mar. 13, 2013.

The Sequence Listing for this application is labeled “Seq-List.txt” which was created on Jan. 30, 2015 and is 28 KB. The entire contents of the sequence listing is incorporated herein by reference in its entirety.

FIELD OF INVENTION

The present invention relates, generally, to pharmacogenetics, and more specifically to genetic markers associated with the clinical response to an FGF-18 compound during treatment of a cartilage disorder. The present invention more particularly relates to human genes, which can be used for the diagnosis and treatment of cartilage disorders.

The invention further discloses specific polymorphisms or alleles of the IL1RN gene that are related to cartilage response to an FGF-18 compound treatment as well as diagnostic tools and kits based on these susceptibility alterations. Thus, the invention can be used in predicting the response to an FGF-18 compound treatment. It could be used for selecting/identifying patients to be treated by intra-articular administration of an FGF-18 compound. The use of these markers in diagnostics could result in increased benefit and reduced risk for patients.

BACKGROUND OF THE INVENTION

Cartilage disorders broadly refer to diseases characterized by degeneration of metabolic abnormalities in the connective tissues which are manifested by pain, stiffness and limitation of motion of the affected body parts. These disorders can be due to pathology or can be the result of trauma or injury. Among others, cartilage disorders include osteoarthritis (OA) and cartilage injury (including sports injuries of cartilage and joints, and surgical injuries such as microfracture(s)). Mature cartilage has limited ability to repair itself, notably because mature chondrocytes have little potential for proliferation and due to the absence of blood vessels. In addition, cartilage is not well nutrified and has a low oxygen pressure. Replacement of damaged cartilage, in particular articular cartilage, caused either by injury or disease is a major challenge for physicians, and available surgical treatment procedures are considered not completely predictable and effective for only a limited time. Therefore, the majority of younger patients either do not seek treatment or are counseled to postpone treatment for as long as possible. When treatment is required, the standard procedure is age-dependent and varies between total joint replacement, transplantation of pieces of cartilage or marrow stimulating technique (such as microfracture). Microfracture is a common procedure that involves penetration of the subchondral bone to stimulate cartilage deposition by bone marrow-derived stem cells. However, it has been shown that this technique does not sufficiently repair the chondral defect and the new cartilage formed is mainly fibrocartilage, resulting in inadequate or altered function and biomechanics. Indeed, fibrocartilage does not have the same durability and may not adhere correctly to the surrounding hyaline cartilage. For this reason, the newly synthesized fibrocartilage may break down more easily (expected time frame: 5-10 years).

For patients with osteoarthritis, non-surgical treatment consists notably of physical therapy, lifestyle modification (e.g., reducing activity), supportive devices, oral and injected drugs (e.g., non-steroidal anti-inflammatory drugs), and medical management. Once these treatments fail, surgery, such as joint replacement, is the main option for the patients. Such an option can provide a reduction in symptoms that is generally only short lived. Tibial or femoral osteotomies (cutting the bone to rebalance joint wear) may reduce symptoms, help to maintain an active lifestyle, and delay the need for total joint replacement. Total joint replacement can provide relief for the symptom of advanced osteoarthritis, but generally requires a change in a patient's lifestyle and/or activity level.

At that time, drug treatments on the market are mainly directed to pain relief. There is not yet a commercially available treatment that restores cartilage damage (see Lotz, 2010).

Fibroblast Growth factor 18 (FGF-18) is a member of the FGF family of proteins, closely related to FGF-8 and FGF-17. It has been shown that FGF-18 is a proliferative agent for chondrocytes and osteoblasts (Ellsworth et al., 2002; Shimoaka et al., 2002). FGF-18 has been proposed for the treatment of cartilage disorders such as osteoarthritis and cartilage injury, either alone (WO2008/023063) or in combination with hyaluronic acid (WO2004/032849).

Sprifermin, which is a truncated form of human FGF-18, is being investigated in clinical trials for treatment of both osteoarthritis and cartilage injury (for more details see for instance NCT01033994, NCT00911469 and NCT01066871). The current dosing regimen for sprifermin is once weekly for 3 weeks (one treatment cycle), the drug being administered via intra-articular injections. This treatment cycle can be repeated. This dosing regimen has been described in WO2008023063.

At that time, OA and cartilage injury treatments with FGF-18, during clinical trials, are provided to patients without predictive information on the response, i.e., without knowledge on whether the treatment will likely be highly effective, moderately effective or show only little or no effect. Currently, numerous treated patient populations exhibit an intermediate/high response to treatment according to the WOMAC scores with sprifermin after at least one treatment cycle, however, others either do not respond to said treatment or respond while presenting high WOMAC scores compared to control.

Here we describe for the first time genetic markers that are associated with the quality of the clinical response to treatment of cartilage disorders such as OA, cartilage injury or microfracture(s) with FGF-18. Such markers are useful for identifying, through genetic screening prior to the treatment, subgroups of patients that are more likely to exhibit a particular response to treatment with FGF-18, such as a very good clinical response to treatment with FGF-18, or on the contrary those for whom the therapy may fail. Knowledge of the type of clinical response of a patient to treatment can be used to optimize therapy or select therapy, such as selecting treatment with FGF-18 as a first line therapy or adapting the dosing regimen. Such information will be clinically useful for the medical management of cartilage disorders, such as OA/cartilage injury, in patients. For example, if an individual with OA or cartilage injury is known to be at increased risk for not responding to the FGF-18 treatment, the physician may exclude said patient from the FGF-18 treatment. In addition, such predictive information may also be clinically useful to guide decisions on the dosing regimen.

SUMMARY OF THE INVENTION

The present invention is directed to a method of predicting the sensitivity to treatment with an FGF-18 compound of a subject having a cartilage disorder, the method comprising the steps of:

-   -   a. Determining, from a nucleic acid sample, the genotype at both         loci IL-1RN rs9005 and IL-1RN rs315952; and     -   b. Predicting from the result of step a high, intermediate, low         or no sensitivity of said subject to treatment with an FGF-18         compound.

According to said method, the presence of the genotype G/G at IL-1RN rs9005 and T/T at IL-1RN rs315952 is predictive of no response or low response (i.e., non-sensitivity) to treatment with an FGF-18 compound. On the contrary, the presence of the genotype A/G or A/A at IL-1RN rs9005 and T/C or C/C at IL-1RN rs315952 is predictive of high response (high sensitivity) to treatment with an FGF-18 compound. The other genotypes at these loci are predictive of intermediate sensitivity (i.e., G/G at IL-1RN rs9005 and T/C or C/C at IL-1RN rs315952 or A/G or A/A at IL-1RN rs9005 and T/T at IL-1RN 315952, or C/C in the complement of IL-1RN rs9005 and A/G or G/G in the complement of IL-1RN rs315952 or T/C or T/T in the complement of IL-1RN rs9005 and A/A in the complement of IL-1RN 315952).

Also described herein is a method for selecting patients having a cartilage disorder for inclusion in or exclusion from treatment, or clinical trials, with an FGF-18 compound, based on the likelihood of their sensitivity to said treatment, comprising determining, from a nucleic acid sample, the genotype at both loci IL-1RN rs9005 and IL-1RN rs315952, wherein the patient's genotype with respect to said loci is predictive of the patient's risk for being sensitive or non-sensitive to said treatment, and selecting sensitive patients as being suitable for said treatment. In particular, patients having the genotype G/G at IL-1RN rs9005 and T/T at IL-1RN rs315952 will be classified as non-sensitives. As such, these subjects could be excluded from the FGF-18 compound treatment, or from clinical trials. It follows that the subjects having any other genotypes at these loci (i.e., G/G at IL-1RN rs9005 and T/C or C/C at IL-1RN rs315952 or A/G or A/A at IL-1RN rs9005 and T/T, T/C or C/C at IL-1RN rs315952) will be classified as sensitives, comprising both intermediate-sensitive and super-sensitive (or high-sensitive) subjects, and thus could be included in (or suitable for) treatment with an FGF-18 compound, or clinical trials.

The present invention further provides a method for selecting patients having a cartilage disorder for an alternative therapeutic regimen with an FGF-18 compound, based on their likelihood of being super-sensitives to FGF-18 compound treatment, comprising determining, from a nucleic acid sample, the genotype at both loci IL-1RN rs9005 and IL-1RN rs315952, wherein the patient's genotype with respect to said loci is predictive of the subject's risk for being super-sensitive to a treatment with said FGF-18 compound and selecting said patient for an alternative therapeutic regimen that would be suitable for said patient. Preferably, in such alternative therapeutic regimen, the total dose of FGF-18 compound that is to be administered could be reduced compared to the dose of FGF-18 compound to be administered to a patient who does not present a risk for being super-sensitive to the FGF-18 compound treatment. In particular, patients having the genotype A/G or A/A at IL-1RN rs9005 together with T/C or C/C at IL-1RN rs315952, being classified as super-sensitives, are selected for an alternative therapeutic regimen in which the dose of FGF-18 to be administered is reduced.

Also provided is a method for selecting patients having a cartilage disorder for an alternative therapeutic regimen with an FGF-18 compound, based on their likelihood of AIR events when treated with an FGF-18 compound, comprising determining, from a nucleic acid sample, the genotype at both loci IL-1RN rs9005 and IL-1RN rs315952, wherein the patient's genotype with respect to said loci is predictive of the subject's risk for developing AIR events in response to treatment with said FGF-18 compound and selecting said patient for an alternative therapeutic regimen that would be suitable for said patient. Preferably, in such alternative therapeutic regimen, the total dose of FGF-18 compound that is to be administered could be reduced compared to the dose of FGF-18 compound to be administered to a patient who does not present a risk for developing AIR events. In particular, patients having the genotype A/G or A/A at IL-1RN rs9005 together with T/C or C/C at IL-1RN rs315952, being classified as at risk for developing AIR events, are selected for an alternative therapeutic regimen in which the dose of FGF-18 to be administered is reduced.

Also encompassed is an FGF-18 compound for use in the treatment of a patient having a cartilage disorder, characterized in that the patient has any combination of the genotype(s) selected from the group consisting of: 1) G/G at IL-1RN rs9005 and T/C or C/C at IL-1RN rs315952, and 2) A/G or A/A at IL-1RN rs9005 and T/T, T/C or C/C at IL-1RN rs315952. Should the patient be classified as super-sensitive, i.e., a subject having the genotypes A/G or A/A at IL-1RN rs9005 together with T/C or C/C at IL-1RN rs315952, said patient could be treated with a reduced dose of FGF-18 compound compared to a subject having one of the two other combinations of genotypes.

In a further aspect, it also describes a kit comprising means for performing the above methods and instructions for use. Said kit includes at least a couple of specific primers or probes for detecting the presence or absence of the alleles.

In particular embodiments of the present invention as a whole, i.e., in any of the methods or uses mentioned herein, the FGF-18 compound to be used as a treatment is sprifermin and the patient has a cartilage disorder selected from the group consisting of osteoarthritis, cartilage injury, fractures affecting joint cartilage, and surgical procedures with impact on joint cartilage (e.g., microfracture).

It is to be understood that in any of the methods or uses mentioned herein, before determining the genotype at one locus, it is necessary to obtain a nucleic acid sample (or a test sample) of said subject, via for instance blood or saliva collection. Alternatively the test sample is selected from buccal cells, urine or stool. Preferably, the nucleic acid sample is a DNA sample. Further, it is also to be understood that any of the methods or uses mentioned herein are performed in vitro, and not on the animal or human body.

It is also to be understand that in the context of the invention as a whole, determination can be performed in the complementary sequence corresponding to IL rs9005 and ILrs315952.

Definitions

The term “FGF-18 compound” or “FGF-18”, as used herein, is intended to be a protein maintaining at least one biological activity of the human FGF-18 protein. FGF-18 may be native, in its mature form, or a truncated form thereof. Biological activities of the human FGF-18 protein include notably the increase in osteoblastic activity (see WO98/16644) or in cartilage formation (see WO2008/023063). Native, or wild-type, human FGF-18 is a protein expressed by chondrocytes of articular cartilage. Human FGF-18 was first designated zFGF-5 and is fully described in WO98/16644. SEQ ID NO:1 corresponds to the amino acid sequence of the native human FGF-18, with a signal peptide consisting of amino acid residues 1(Met) to 27(Ala). The mature form of human FGF-18 corresponds to the amino acid sequence from residue 28(Glu) to residue 207(Ala) of SEQ ID NO: 1 (180 amino acids). The term also includes fusion protein, wherein FGF-18 protein is coupled with a heterologous protein or a chemical compound.

FGF-18, in the present invention, may be produced by recombinant methods, such as taught by WO2006/063362. Depending on the expression systems and conditions, FGF-18 in the present invention is expressed in a recombinant host cell with a starting methionine (Met) residue or with a signal sequence for secretion. When expressed in prokaryotic host, such as in E. coli, FGF-18 contains an additional Met residue in the N-terminal of its sequence. For instance, the amino acid sequence of human FGF-18, when expressed in E. coli, starts with a Met residue in N-term (position 1) followed by residues 28 (Glu) to residue 207 (Ala) of SEQ ID NO: 1.

The term “truncated form” of FGF-18, as used herein, refers to a protein which comprises or consists of residues 28 (Glu) to 196 (Lys) of SEQ ID NO: 1. Preferably, the truncated form of the FGF-18 protein is the polypeptide designated “trFGF-18” (170 amino acids), which starts with a Met residue (in N-terminal) followed by amino acid residues 28 (Glu) to 196 (Lys) of the wild-type human FGF-18. The amino acid sequence of trFGF-18 is shown in SEQ ID NO:2 (amino acid residues 2 to 170 of SEQ ID NO:2 correspond to amino acid residues 28 to 196 of SEQ ID NO:1). trFGF-18 is a recombinant truncated form of human FGF-18, produced in E. coli (see WO2006/063362). The International Nonproprietary Name (INN) for this particular form of FGF-18 is sprifermin. Sprifermin has been shown to display similar activities as the mature human FGF-18, e.g., it increases chondrocyte proliferation and cartilage deposition, leading to repair and reconstruction of a variety of cartilaginous tissues (see WO2008/023063).

The term “cartilage disorder”, as used herein, encompasses disorders resulting from damages due to injury, such as traumatic injury, chondropathy or arthritis. Examples of cartilage disorders that may be treated by the administration of the FGF-18 formulation described herein include but are not restricted to arthritis, such as osteoarthritis, cartilage injury, fractures affecting joint cartilage and surgical procedures with impact on joint cartilage (e.g., microfracture). Degenerative diseases/disorders of the cartilage or of the joint, such as chondrocalcinosis, polychondritis, relapsing polychondritis, ankylosing spondylitis or costochondritis, are also encompassed by this wording. The International Cartilage Repair Society has proposed an arthroscopic grading system to assess the severity of the cartilage defect: grade 0: (normal) healthy cartilage, grade 1: the cartilage has a soft spot or blisters, grade 2: minor tears visible in the cartilage, grade 3: lesions have deep crevices (more than 50% of the cartilage layer), and grade 4: the cartilage tear exposes the underlying (subchronal) bone (see for instance page 13 of Worldwide Website:cartilage.orgLfiles/contentmanagement/ICRS_evaluation. pdf).

The term “osteoarthritis” is used to intend the most common form of arthritis. The term “osteoarthritis” encompasses both primary osteoarthritis and secondary osteoarthritis (see for instance The Merck Manual, 17^(th) edition, page 449). The most common way of classifying/grading osteoarthritis is the use of the Kellgren-Lawrence radiographic grading scale (see table below). Osteoarthritis may be caused by the breakdown of cartilage. Bits of cartilage may break off and cause pain and swelling in the joint between bones. Over time, the cartilage may wear away entirely, and the bones will rub together. Osteoarthritis can affect any joint but usually concerns hands and weight-bearing joints such as hips, knees, feet, and spine. In a preferred example, the osteoarthritis may be knee osteoarthritis or hip osteoarthritis. Osteoarthritis is one of the preferred cartilage disorders that can be treated by administering the FGF-18 compounds according to the present invention.

The Kellgren-Lawrence Radiographic Grading Scale of Osteoarthritis is described as follows:

Grade of Osteoarthritis Description 0-None No radiographic findings of osteoarthritis 1-Doubtful Doubtful narrowing of joint space and possible osteophytic lipping 2-Minimal Definite osteophytes, definite narrowing of joint space 3-Moderate Moderate multiple osteophytes, definite narrowing of joints space, some sclerosis and possible deformity of bone contour 4-Severe Large osteophytes, marked narrowing of joint space, severe sclerosis and definite deformity of bone contour

The term “cartilage injury” as used herein is a cartilage disorder or cartilage damage resulting notably from a trauma. Cartilage injuries can occur notably after traumatic mechanical destruction, notably further to an accident or surgery (for instance microfracture surgery). The term “cartilage injury” also includes chondral or osteochondral fracture, damage to meniscus, and microfracture. Also considered within this definition is sport-related injury or sport-related wear of tissues of the joint.

The term AIR (acute inflammatory reaction) as used herein is defined as follows. Within a 1 to 7-day period, preferably within a 3-day period, following the intra-articular injection of an FGF-18 compound in the target knee, both the following criteria must be fulfilled:

-   -   Self-reported swelling (synovial fluid effusion)     -   Pain increase by 30 mm on 100 mm Visual Analogue Scale (VAS)

An “allele” is a particular form of a gene, genetic marker or other genetic locus that is distinguishable from other forms of the gene, genetic marker or other genetic locus, e.g., without limitation by its particular nucleotide sequence. The term allele also includes for example without limitation one form of a single nucleotide polymorphism (SNP). An individual can be homozygous for a certain allele in diploid cells; i.e., the allele on both paired chromosomes is identical, or heterozygous for said allele, i.e., the alleles on both paired chromosomes are not identical.

The term “genetic marker”, “biomarker” or “marker” refers to an identifiable polymorphic (genetic) locus. An example without limitation of a genetic marker is a single nucleotide polymorphism (SNP).

A “single nucleotide polymorphism (SNP)” is a DNA sequence variation occurring when a single nucleotide—A (for Adenine), T (for Thymine), C (for Cytosine), or G (for Guanine)-in the genome (or other sequence shared between individuals of a species) differs between individuals of a species (or between paired chromosomes in an individual). An SNP is frequently preceded by and followed by highly conserved sequences in the population of interest and thus the location of an SNP is typically made in reference to a consensus nucleic acid sequence of thirty to sixty nucleotides that bracket the genetic marker locus, which is sometimes referred to as a context sequence for the SNP. The SNPs that were analyzed by the present inventors in connection with treatment of cartilage disorders with sprifermin are those shown in Table 1.

A “genotype” as used herein refers to the combination of both alleles of a genetic marker, e.g., without limitation of an SNP, on a single genetic locus on paired (homologous) chromosomes in an individual. “Genotype” as used herein also refers to the combination of alleles of more than one genetic loci, e.g., without limitation of SNPs, on a pair or more than one pair of homologous chromosomes in an individual.

The term “haplotype” refers to variants or alleles from distinct markers (e.g., SNPs) that are co-located on the same chromosome. SNP genotype data, as measured from SNP arrays or Taqman assays, are unphased (i.e., the chromosome's parent of origin is unknown for each allele). Computational methods (Browning and Browning, 2011) use information across individuals to estimate (i.e., infer) haplotype phase from genotype data.

The term “Genotyping” refers to a process for determining a genotype of an individual, either for a single SNP or many SNPs.

“Locus” or “genetic locus” refers to a specific location on a chromosome or other genetic material. For instance, IL-1RN rs9005 is a locus and can be called, in the frame of the present invention, either “IL-1RN rs9005” or “locus IL-1RN rs9005”. The same applies to IL-1RN rs315952. As is self-evident for the skilled person, from the NCBI database for these SNPs, the genotype to be determined at both IL-1RN rs9005 and IL-1RN rs315952 is the one in position 27 of each of these loci, i.e., position 27 of SEQ ID NO:6 and position 27 of SEQ ID NO:7.

The term “SNP1” in the context of the present invention is position 27 of SEQ ID NO: 6, also identified as rs9005 in the NCBI database. SEQ ID NO. 6 is a portion of the genomic nucleic acid sequence of interleukin 1 receptor antagonist (IL-1RN). The terms “IL-1RN rs9005”, “rs9005” and “SNP1” are used interchangeably.

The term “SNP2” refers to position 27 of SEQ ID NO: 7 identified as being rs315952 in the NCBI database. SEQ ID NO: 7 is a portion of the genomic nucleic acid sequence of IL-1RN. The terms “IL-1RN rs315952”, “rs315952” and “SNP2” are used interchangeably.

The term “probe” or “primer” refers to an oligonucleotide, i.e., a nucleic acid or a nucleic acid derivative, including without limitation a locked nucleic acid (LNA), peptide nucleic acid (PNA) or bridged nucleic acid (BNA), that is usually between 5 and 100 contiguous bases in length, and most frequently between 5-40, 5-35, 5-30, 5-25, 5-20, 5-15, 5-10, 10-50, 10-40, 10-30, 10-25, 10-20, 15-50, 15-40, 15-30, 15-25, 15-20, 20-50, 20-40, 20-30 or 20-25 contiguous bases in length. The sequence of a probe/primer can be designed to specifically hybridize to one of the allelic forms of a genetic marker; such oligonucleotides are referred to as allele-specific probes. If the genetic marker is an SNP, the complementary allele for that SNP can occur at any position within an allele-specific probe. Other probes/primers useful in practicing the invention specifically hybridize to a target region adjacent to an SNP with their 3′ terminus located one to less than or equal to about 10 nucleotides from the genetic marker locus, preferably about 5 nucleotides. Such probes/primers hybridizing adjacent to an SNP are useful in polymerase-mediated primer extension methods and are referred to herein as “primer-extension oligonucleotides.” In a preferred embodiment, the 3′-terminus of a primer-extension oligonucleotide is a deoxynucleotide complementary to the nucleotide located immediately adjacent an SNP.

The term “polymorphism” refers to two or more alternate forms (alleles) in a population of a genetic locus that differ in nucleotide sequence or have variable numbers of repeated nucleotide units. Polymorphisms occur in coding regions (exons), non-coding regions of genes or outside of genes (intergenic regions). The different alleles of a polymorphism typically occur in a population at different frequencies, with the allele occurring most frequently in a selected population sometimes referenced as the “major” or “wild-type” allele. Diploid organisms may be homozygous or heterozygous for the different alleles that exist. A biallelic polymorphism has two alleles.

The term “epistasis” is generally used to define the interaction between genes. Epistasis was first defined by Bateson (Bateson and Mendel, 1909) to describe a masking effect whereby a variant or allele at one locus prevents the variant at another locus from manifesting its effect. However, the scientific literature provides many different definitions (Phillips, 1998; Cordell, 2002). Herein, epistasis was tested as the statistical interaction between genotypes from two distinct SNPs. This is similar to the definition proposed by Fisher in 1918 (Fisher, 1918), i.e., a deviation from additivity in the effect of alleles at different loci with respect to their contribution to a phenotype.

“WOMAC total scores” or “WOMAC scores” (“WOMAC” for “Western Ontario and McMaster Universities Osteoarthritis Index”) measure pain (WOMAC pain score), function (WOMAC function score) and stiffness (WOMAC stiffness score). When applied to assessment of pain and dysfunction associated with cartilage injury, it consists of a questionnaire containing 24 items divided into 3 subscales (5 items for Pain, 2 items for Stiffness and 17 items for Physical Function) (see Bellamy et al., 1988; Wolfe, 1999). It is a well-known instrument, widely used notably in the assessment of OA severity.

In order to evaluate cartilage repair, cartilage volume measurements were performed through magnetic resonance imaging (MRI) measurements, including Total volume of cartilage (also referred as LFTC (lateral femoro-tibial compartment)+MFTC (medial femoro-tibial compartment)), Lateral volume of cartilage (also referred as LFTC), Medial volume of cartilage (also referred as MFTC), and new total average cartilage thickness.

The term “baseline” means before treatment (i.e., at study entry). It refers notably to clinical variables, such as, but not limited to, the cartilage volume and WOMAC total score of a given patient at study entry (i.e., before treatment with FGF-18 compound or placebo).

“Sensitives” are patients that exhibit a response to treatment of a cartilage disorder with an FGF-18 compound. Preferably, sensitive patients (or patients showing sensitivity to treatment) exhibit a notably higher increase in total cartilage volume than placebo-treated subjects, i.e., they show cartilage repair. In addition, sensitive patients exhibit at least similar improvement in WOMAC total scores than placebos. The terms “super-sensitives”, “intermediate-sensitives” and “non-sensitives” refer to the different groups of patients depending notably on the increase of the cartilage volume following FGF-18 compound treatment. Super-sensitives display a high response (i.e., high cartilage repair) to treatment with an FGF-18 compound, intermediate-sensitives display a good or intermediate response (i.e., good or intermediate cartilage repair) to treatment with an FGF-18 compound, and non-sensitives display no or low response to treatment with an FGF-18 compound. Both super-sensitive and sensitive subjects have similar improvement in WOMAC total scores than placebos. Conversely, non-responders have significantly smaller improvement in WOMAC total score than placebos. The terms “super-sensitives” and “high-sensitives” are used interchangeably. It is noted that super-sensitives have been shown to present higher risk of AIR events.

More particularly, the terms “intermediate-sensitives”, “super-sensitives”, and “non-sensitives” include, but are not limited to, the different groups of patients depending on the increase of the cartilage volume and improvement of WOMAC total scores following FGF-18 compound treatment.

The proposed criteria for sensitives are the following:

-   -   1. Positive cartilage increase (between +10 and +100 mm³)         compared to baseline,     -   2. Cartilage increase change significantly higher than change in         placebo (e.g., as tested with a linear model adjusting for BMI,         KL grade, sex and age and with alpha=5%),     -   3. WOMAC score improvement, i.e, diminution (e.g., more than 5         points reduction) compared to baseline, and     -   4. WOMAC score change not significantly higher than change in         placebo (e.g., as tested with a linear model adjusting for BMI,         KL grade, sex and age and with alpha=5%).

The proposed criteria for super-sensitives are the same as for sensitives, but with cartilage increase greater than 100 mm³ (criterion #1) compared to baseline.

Non-sensitives can be defined as subjects not fulfilling criteria #1 or #2 and not fulfilling criteria #3 or #4.

Thus, intermediate sensitives display a good or intermediate response (or a good or intermediate sensitivity) to treatment with an FGF-18 compound (see above criteria; according to the examples, median change: +84.81 mm³ total cartilage volume increase compared to baseline; median change: −20 points on the WOMAC total score compared to baseline; and non-significant difference in WOMAC total score compared to placebos). Super-sensitives display a high response (or a high sensitivity) to treatment with an FGF-18 compound (see above criteria; according to the examples, median change: +119.46 mm³ total cartilage volume increases compared to baseline, representing a +40.85% increase (i.e., benefit) compared to sensitive subjects; median change: −10 points on the WOMAC total score compared to baseline; and non-significant difference in WOMAC total score compared to placebos). Non-sensitives display no or low response (or no or low sensitivity) to treatment with an FGF-18 compound (see above criteria; according to the examples: significantly smaller increase in total cartilage volume compared to placebos (difference between medians: −106.64 mm³); little improvement (median change: −1 point) in WOMAC total scores compared to baseline; and significant difference in WOMAC total score compared to placebos).

The “response” or “sensitivity” to an FGF-18 compound treatment is to be understood as 1 year after the first injection and measured as 1) increase of cartilage volume, measured owing to MRI or X-Ray for instance, 2) decrease of WOMAC total scores, and 3) changes in WOMAC total scores not significantly higher than those of placebos (refer also to the definition of “sensitive”).

A “prognostic biomarker” is informative about the subject's condition, including and not limited to disease evolution, disease severity or disease outcome, regardless of any therapy. A “predictive biomarker” is informative about the effect of a received therapy, including and not limited to efficacy and safety outcome. The prognostic and predictive definitions are not mutually exclusive, thus a biomarker can be both prognostic and predictive.

As used in the present invention, the term “MAD” means Multiple Ascending Dose. When this acronym is followed by a figure, the figure corresponds to the dose at which an FGF-18 compound has been injected during treatment. For instance MAD100 refers to a treatment during which a patient received 100 mcg of an FGF-18 compound per injection. The abbreviation “PL” (and “MADPL”) refers to placebo.

The term “storage device”, as used herein, is intended to include any suitable computing or processing apparatus or other device configured or adapted for storing data or information. Examples of electronic apparatus suitable for use with the present invention include stand-alone computing apparatus, data telecommunications networks, including local area networks (LAN), wide area networks (WAN), Internet, Intranet, Extranet, and local and distributed computer processing systems. Storage devices also include, but are not limited to, magnetic storage media, such as floppy discs, hard disc storage media, magnetic tape, optical storage media such as CD-ROM, DVD, electronic storage media such as RAM, ROM, EPROM, EEPROM and the like, general hard disks and hybrids of these categories such as magnetic/optical storage media.

As used herein, the term “stored” refers to a process for encoding information on the storage device. Those skilled in the art can readily adopt any of the presently known methods for recording information on known media to generate manufactures comprising expression level information.

DETAILED DESCRIPTION OF THE INVENTION

There is a need to predict the clinical efficacy (notably with regards to cartilage repair) of an FGF-18 compound treatment for the treatment of patients having a cartilage disorder, such as osteoarthritis, cartilage injury, fractures affecting joint cartilage or surgical procedures with impact on joint cartilage (e.g., microfracture). To optimize the treatment of said patients, it is important to identify biomarkers that could be used as predictors of the response of a given patient to the FGF-18 compound treatment, notably with regard to cartilage repair. Such predictive biomarkers may be used to identify high-risk groups of either non-sensitives or on the contrary super-sensitives to the treatment. For instance, if one patient having osteoarthritis is known to be at high risk for non-responding (or for being non-sensitive) to the treatment, the physician may decide not to propose an FGF-18 compound, such as sprifermin, to said patient. On the contrary, if one patient having osteoarthritis is known to be at high risk for being super-sensitive to the treatment, the physician may decide to adapt the dose regimen, in order to lower the dose of FGF-18 to be administered to said patient. Such predictive information may be clinically useful to guide medical decisions, notably on the timing of joint replacement surgery when needed.

The surprising finding of the present invention is based on a study aimed at identifying potential biomarkers associated with sprifermin administration. The biomarkers used in this study were composed of both candidate genetic markers (see Table 1) and less than 1 million SNPs covering the human genome with a median marker spacing of 680 bases. The association between genetic markers and clinical response variables was assessed. The rationale behind this type of analysis was to identify biomarkers that could be predictive of the clinical outcome (notably with regard to cartilage repair) for a patient to be treated with an FGF-18 compound such as sprifermin. These SNPs could be used to stratify and target specific patient populations.

The inventors have surprisingly found an association with certain biomarkers (or SNPs) and outcome (e.g., cartilage repair) as well as adverse effects of the FGF-18 therapy. Of special interest are the SNPs rs9005 and rs315952, both located in the IL-1RN gene (see FIG. 1).

These biomarkers have been described in the literature as being possibly related to disease severity and progression in OA patients (see for instance WO2009/135218 or Attur et al., 2010), using a haplotype (the so-called C-T-A haplotype) that includes rs419598 (C), rs315952 (T) and rs9005 (A). Interestingly, although two of these biomarkers, i.e., rs9005 and rs315952, are strongly correlated with responsiveness to FGF-18 treatment, as shown in the present invention, the third one, i.e., rs419598, does not appear being further involved in the observed phenotype, although described, in the literature, as being linked to the two other SNPs. Indeed, the so-called C-T-A haplotype did not allow stratifying subjects for change in total cartilage volume (FIG. 2) nor change in WOMAC total score (FIG. 3). Thus the C-T-A haplotype was not identified as a good predictor of the response to FGF-18 therapy.

On the contrary, it has been surprisingly found by the present inventors that the alleles A of the biomarker rs9005 together with C of the biomarker rs315952 are associated with a better response to treatment with an FGF-18 compound, such as sprifermin, in subjects afflicted with cartilage injury (Table 4). These subjects are called super-sensitives or high-sensitives.

On the contrary, it has also surprisingly been found by the present inventors that the genotype rs315952 T/T together with rs9005 G/G is associated with an absence of, or low, response to treatment with an FGF-18 compound (i.e., non-sensitivity to treatment with an FGF-18 compound), such as sprifermin, in subjects afflicted with cartilage disorder (Table 4). These subjects are called non-sensitives. It follows that patients having any other genotype at both loci (i.e., G/G at IL-1RN rs9005 and T/C or C/C at IL-1RN rs315952 or A/G or A/A at IL-1RN rs9005 and T/T at IL-1RN 315952) are intermediate sensitives.

Therefore, it is a finding of the present invention that polymorphic loci IL-1RN rs9005 and IL-1RN rs315952 can be used in combination as predictive biomarkers of responsiveness of one subject to FGF-18 compound treatment, such as sprifermin (Table 4). Preferably, the subject has a cartilage disorder, such as osteoarthritis, cartilage injury, fractures affecting joint cartilage or surgical procedures with impact on joint cartilage (e.g., microfracture). In a particular embodiment, the subject will be predicted to be non-sensitive to FGF-18 compound treatment if he has the genotype IL-1RN rs9005 G/G together with IL-1RN rs315952 T/T. On the contrary, the subject will be predicted to be a super-sensitive (or a high-sensitive) to FGF-18 compound treatment if he has the genotype IL-1RN rs9005 A/G or A/A together with IL-1RN rs315952 T/C or C/C. In any other case, the patient will be predicted to be intermediate sensitive to FGF-18 compound treatment (see Table 22 for summary of clinical outcomes and potential therapeutic options).

The present invention is therefore directed to a method of predicting the sensitivity to treatment with an FGF-18 compound of a subject having a cartilage disorder, the method comprising the steps of:

-   -   a. Determining the genotype at both IL-1RN rs9005 and IL-1RN         rs315952; and     -   b. Predicting from the result of step a high, intermediate, low         or no sensitivity of said subject to treatment with an FGF-18         compound.

Before determining the genotype at one locus, it is necessary to obtain a nucleic acid sample of said subject, for instance by blood or saliva collection. Preferably, the nucleic acid sample is a DNA sample. Thus, the present invention is directed to a method of predicting the sensibility to treatment with an FGF-18 compound in a subject having a cartilage disorder, the method comprising the steps of:

-   -   a. Obtaining a nucleic acid sample of said subject;     -   b. Determining, from said nucleic acid sample, the genotype at         both IL-1RN rs9005 and IL-1RN rs315952; and     -   c. Predicting from the result of step b the probability of a         high, intermediate or low or no sensitivity to treatment with an         FGF-18 compound.

According to said method, the presence of the genotype G/G at IL-1RN rs9005 and T/T at IL-1RN rs315952 is predictive of absence of, or low, response to treatment with an FGF-18 compound. The patient will thus be predicted to be non-sensitive. On the contrary, the presence of the genotype A/G or A/A at IL-1RN rs9005 and T/C or C/C at IL-1RN rs315952 is predictive of high response to treatment with an FGF-18 compound. The patient will thus be predicted to be super-sensitive. It follows that the subjects having any other genotypes at these loci (i.e., G/G at IL-1RN rs9005 and T/C or C/C at IL-1RN rs315952 or A/G or A/A at IL-1RN rs9005 and T/T at IL-1RN 315952) will be classified as having intermediate sensitivity to treatment with an FGF-18 compound. From said prediction, the doctor can easily select only those patients that are predicted to be sensitives to FGF-18 compound treatment, including both intermediate-sensitives and super-sensitives.

The present invention also relates to an assay to determine sensitivity to an FGF-18 compound treatment or to determine a treatment regimen with an FGF-18 compound, the assay comprising: (a) subjecting a test sample from a human subject, diagnosed as having a cartilage disorder, to at least one genotyping assay that determines the genotypes of at least two loci, wherein said at least two loci are: (i) SNP1 and (ii) SNP2, (b) determining the genotypes of said at least two loci; (c) selecting a patient as being sensitive to a treatment with an FGF-18 compound when at least one of the following combinations of SNPs is determined to be present: (i) SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6; and SNP2 genotype T/C or CC, or A/G or GG in the complement of the SEQ ID NO: 7; or (ii) SNP1 genotype A/G or AA, or T/C or T/T in the complement of the SEQ ID NO: 6; and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7, or (iii) SNP1 genotype A/G or A/A, or T/C or T/T in the complement of SEQ ID NO:6 and SNP2 genotype T/C or C/C, or A/G or G/G in the complement of SEQ ID No:7 and (d) optionally treating the patient selected in step (c) with an FGF-18 compound.

When the above assay is performed to determine a treatment regimen with an FGF-18 compound, step (c) is optional, whereas step (d) is preferably performed, or is performed.

The present invention further relates to an assay to determine non-sensitivity to an FGF-18 compound treatment, the assay comprising: (a) subjecting a test sample from a human subject diagnosed as having a cartilage disorder to at least one genotyping assay that determines the genotypes of at least two loci, wherein said at least two loci are: (i) SNP1 and (ii) SNP2, (b) determining the genotypes of said at least two loci; (c) selecting a patient as being non-sensitive to a treatment with an FGF-18 compound when the following combinations of SNPs are determined to be present: SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6; and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7, and (d) optionally treating the patient selected in step (c) with a therapeutic compound other than an FGF-18 compound.

Before determining the genotype at one locus, in the above disclosed assays, it is necessary to obtain a nucleic acid (or test) sample of said subject, for instance by blood or saliva collection.

The present application also encompasses a method for selecting patients having a cartilage disorder for inclusion in or exclusion from treatment, or clinical trial, with an FGF-18 compound, based on the likelihood of their response to said treatment, comprising:

-   -   a. Determining, from a nucleic acid sample, the genotype at both         loci IL-1RN rs9005 and IL-1RN rs315952, wherein the patient's         genotype with respect to said loci is predictive of the         patient's risk for being sensitive or non-sensitive to said         treatment, and     -   b. Selecting patients that are suitable for said treatment or         clinical trial, i.e., selecting the sensitive patients as being         suitable for said treatment or said clinical trial.

Before determining the genotype at one locus, it is necessary to obtain a nucleic acid sample of said subject, for instance by blood or saliva collection. Preferably, the nucleic acid sample is a DNA sample. Thus, the present invention encompasses a method for selecting patients having a cartilage disorder for inclusion in or exclusion from treatment, or clinical trial, with an FGF-18 compound, based on the likelihood of their response to said treatment or clinical trial, comprising:

-   -   a. Obtaining a nucleic acid sample of said subject,     -   b. Determining, from a nucleic acid sample, the genotype at both         loci IL-1RN rs9005 and IL-1RN rs315952, wherein the patient's         genotype with respect to said loci is predictive of the         patient's risk for being sensitive or not sensitive to said         treatment, and     -   c. Selecting patients that are suitable for said treatment or         said clinical trial, i.e., selecting the sensitive patients as         being suitable for said treatment or said clinical trial.

According to said method, patients having the genotype IL-1RN rs9005 G/G and IL-1RN rs315952 T/T, who are predicted being non-sensitives, are preferably excluded from the FGF-18 compound treatment, or from clinical trial related to FGF-18 compound. The other patients, the sensitive ones (including both intermediate-sensitives and super-sensitives; i.e., patients having the genotype G/G at IL-1RN rs9005 and T/C or C/C at IL-1RN rs315952 or A/G or A/A at IL-1RN rs9005 and T/T, T/C or C/C at IL-1RN rs315952) can be selected as suitable for the treatment with an FGF-18 compound, such as sprifermin.

Alternatively, the method for selecting a patient having a cartilage disorder for inclusion in or exclusion from treatment or clinical trial with an FGF-18 compound based on the likelihood of the patient's sensitivity to said FGF-18 compound comprised the steps of: (a) subjecting a test sample from a human subject, who is diagnosed as having cartilage disorder, to at least one genotyping assay adapted to determine the genotypes of at least two loci, wherein said at least two loci are: (i) SNP1 and SNP2, wherein SNP2 is position 27 of SEQ ID NO: 7 identified by rs315952, wherein the SEQ ID NO. 7 is a portion of genomic nucleic acid sequence of interleukin 1 receptor antagonist (IL-1RN); and (b) detecting from the genotypes of said at least two loci the presence of a genotype combination selected from: (i) SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6; and SNP2 genotype T/C or CC, or A/G or GG in the complement of the SEQ ID NO: 7; or (ii) SNP1 genotype A/G or AA, or T/C or T/T in the complement of the SEQ ID NO: 6; and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7; or (iii) SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6 and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7; and (c) selecting a patient for inclusion in treatment or clinical trial with an FGF-18 compound when conditions (i) or (ii) are detected based on the recognition that the genotype combinations (i) and (ii) are associated with a response to said FGF-18 compound, and excluding the patient from treatment or clinical trial with an FGF-18 compound when condition (iii) is detected based on the recognition that the genotype combination (iii) is associated with inadequate response to treatment with said FGF-18 compound.

The method for selecting a human subject for a clinical trial for testing an FGF-18 compound may alternatively comprise the steps of: (a) assaying a biological sample from a human subject diagnosed with a cartilage disorder for at least the following two single nucleotide polymorphisms: (i) SNP1 and (ii) SNP2; (b) determining the genotypes of the SNPs; and (c) selecting for the clinical trial the human subject who carries one of the following genotypes in said SNPs: (i) SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6; and SNP2 genotype T/C or CC, or A/G or GG in the complement of the SEQ ID NO: 7; or (ii) SNP1 genotype A/G or AA, or T/C or T/T in the complement of the SEQ ID NO: 6; and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7; or (iii) a human subject who does not carry SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6 and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7.

The present invention also describes a method of excluding a human subject from a clinical trial testing an FGF-18 compound, the method comprising the steps of: (a) assaying a biological sample from a human subject diagnosed with a cartilage disorder for at least the following two single nucleotide polymorphisms: (i) SNP1 and (ii) SNP2; (b) determining the genotypes of the SNPs; and (c) excluding from the clinical trial the human subject who carries the following genotype in said SNPs: SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6 and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7; or excluding from the clinical trial the human subject who does not carry either of the following SNP genotypes: (i) SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6; and SNP2 genotype T/C or CC, or A/G or GG in the complement of the SEQ ID NO: 7; or (ii) SNP1 genotype A/G or AA, or T/C or T/T in the complement of the SEQ ID NO: 6; and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7.

Besides the finding that as a function of his/her genotype, the subject could be classified as super-sensitive, sensitive or non-sensitive, it has surprisingly been found that the same genotype is also predictive of adverse events, such as AIRs. Indeed, further investigation and analysis of the SNP polymorphisms demonstrated a relation between the markers rs9005 and rs315952, in combination, with adverse events in the clinic, with MRI data concerning structural benefit and with symptomatic benefit as determined using the WOMAC questionnaire. Not only can these SNPs be used as a predictive tool of the patient's response to a treatment with an FGF-18 compound at cartilage volume level, but can also be used as a predictive tool of his/her risk to develop adverse events such as AIRs. Thus, the profile “structural benefit vs. potential adverse effects” of FGF-18 therapy would be useful to determine a better risk/benefit ratio, i.e., better outcome with lower risk of side effects in the patients.

This is based on the finding that the super-sensitives have higher WOMAC scores and higher likelihood of having an AIR event, notably when an FGF-18 compound is used, for instance at a dose of 100 mcg, compared to patients treated with the placebo. Similarly, the non-sensitives also have high WOMAC scores, at any dose, compared to patients treated with the placebo. It has also been shown that contrary to the results of a dose of 100 mcg, super-sensitives treated with an FGF-18 compound at a lower dose, for instance 30 mcg, have lower WOMAC scores (i.e., better WOMAC improvement) and lower likelihood of having an AIR event. In view of these results, it can be useful to select the patients based on their likelihood to respond/not respond to the FGF-18 compound treatment in combination with their risk level to present adverse events: the non-sensitives could be excluded from a treatment that is likely not to work for them (see above method of selection), and the super-sensitives may be subjected to an alternative treatment regimen.

The present invention is thus also directed to a method for selecting patients having a cartilage disorder for an alternative therapeutic regimen with an FGF-18 compound, based on their likelihood of being super-sensitives to FGF-18 compound treatment, comprising identifying the patient's nucleic acid at both of the polymorphic loci selected from the group consisting of IL-1RN rs9005 and IL-1RN rs315952, wherein the patient's genotype with respect to said loci is predictive of the subject's risk for being super sensitive to a treatment with said FGF-18 compound and allows the selection of said patient for an alternative therapeutic regimen that would be suitable for said patient, in which alternative therapeutic regimen the dose of FGF-18 compound that is to be administered is reduced compared to the dose of FGF-18 compound to be administered to a patient who is predicted to be sensitive but not super-sensitive to said FGF-18 compound treatment.

Also described herein is a method for selecting a patient having a cartilage disorder for a modified treatment regimen with an FGF-18 compound based on the likelihood of said patient of having Acute Inflammatory Reaction (AIR) events when treated with said compound, the method comprising the steps of (a) detecting from a nucleic acid sample obtained from the patient the genotype of (i) SNP1 and (ii) SNP2; and (b) selecting a modified treatment regimen for a patient when a combination of SNP1 genotype A/G or AA, or T/C or T/T in the complement of the SEQ ID NO: 6; and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7 is detected.

Accordingly, patients having the genotype IL-1RN rs9005 A/G or A/A and IL-1RN rs315952 T/C or C/C, who are predicted to be super-sensitives, are preferably selected for an alternative therapeutic regimen in which the dose of FGF-18 compound to be administered is reduced.

Also described herein is a method for selecting patients having a cartilage disorder for an alternative therapeutic regimen with an FGF-18 compound, based on their likelihood of having AIR events when treated with an FGF-18 compound, comprising determining, from a nucleic acid sample, the genotype at both loci IL-1RN rs9005 and IL-1RN rs315952, wherein the patient's genotype with respect to said loci is predictive of the subject's risk for developing AIR events in response to treatment with said FGF-18 compound, and allows the selection of said patient for an alternative therapeutic regimen that would be suitable for said patient, in which alternative therapeutic regimen the dose of FGF-18 compound that is to be administered is reduced compared to the dose of FGF-18 compound to be administered to a patient who (1) is predicted to be sensitive and (2) does not present a risk for developing AIR events.

Accordingly, patients having the genotype A/G or A/A at IL-1RN rs9005 and T/C or C/C at IL-1RN rs315952, who are predicted to be super-sensitives, are preferably selected for an alternative therapeutic regimen in which the dose of FGF-18 to be administered is reduced, compared to the normal therapeutic regimen, i.e., the regimen for a patient who is predicted to be sensitive to FGF-18 compound treatment but who does not present a risk for developing AIR events.

The FGF-18 compound is usually to be administered intra-articularly at a dose of 100 mcg per injection, once weekly for 3 weeks per treatment cycle. In view of the good results at 30 mcg for the super-sensitives (see examples), a proposed alternative dosing regimen for those patients predicted to be super-sensitives is intra-articular administration of the FGF-18 compound at a dose of 30 mcg per injection, once weekly for 3 weeks per treatment cycle. It is to be understood that although at that time, the preferred dose is 100 mcg per injection, possibly reduced to 30 mcg per injection for super-sensitives, the present invention is not limited to said dosages. Therefore, the FGF-18 compound can be administered intra-articularly at a dose comprised between 50 and 300 mcg per injection, preferably between 60 and 250 mcg or even preferably between 100 and 200 mcg. For super-sensitive patients, said dose could be reduced, to ½ or to ⅓ for instance.

The present invention further encompasses an FGF-18 compound for use in the treatment of a patient having a cartilage disorder, characterized in that the patient has any combination of the genotype(s) selected from the group consisting of: (1) IL-1RN rs9005 G/G and IL-1RN rs315952 T/C or C/C, or (2) IL-1RN rs9005 A/G or A/A and IL-1RN rs315952 T/T, T/C or C/C. In addition, a patient bearing at least one A allele from IL-1RN rs9005 and at least one C allele from IL-1RN rs315952 T/T is eligible for FGF-18 compound treatment at a lower dose. It follows that a patient who does not meet these criteria (i.e., with genotype IL-1RN rs9005 G/G and IL-1RN rs315952 T/T) is preferably excluded from FGF-18 compound treatment (see Table 22).

The present invention is also directed to an assay for selecting a treatment regimen for a human subject with a cartilage disorder, the assay comprising: (a) subjecting a test sample from the human subject who is diagnosed as having a cartilage disorder to at least one genotyping assay that determines the genotypes of at least two loci, wherein said at least two loci are: (i) SNP1 and (ii) SNP2; (b) detecting from the genotypes of said at least two loci the presence of a genotype combination selected from: (i) SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6; and SNP2 genotype T/C or CC, or A/G or GG in the complement of the SEQ ID NO: 7; or (ii) SNP1 genotype A/G or AA, or T/C or T/T in the complement of the SEQ ID NO: 6; and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7; or (iii) SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6 and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7; and (c) selecting, and optionally administering, a treatment regimen comprising an effective amount of an FGF-18 compound when condition (i) or (ii) is detected based on the recognition that the genotype combinations (i) and (ii) are associated with a response to said compound, and excluding the treatment regimen comprising said compound when condition (iii) is detected based on the recognition that the genotype combination (iii) is associated with inadequate response to treatment with said compound.

Also described is a method for treating a human subject with a cartilage disorder, comprising administering a composition comprising an effective amount of an FGF-18 compound to a human subject who is diagnosed as having a cartilage disorder, and who is further determined to carry the combination of the single nucleotide polymorphisms (SNPs) selected from: (i) SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6, wherein SNP1 is position X of SEQ ID NO: 6 identified by rs9007, wherein the SEQ ID NO: 6 is a portion of genomic nucleic acid sequence of interleukin 1 receptor antagonist (IL-1RN); and SNP2 genotype T/C or CC, or A/G or GG in the complement of the SEQ ID NO: 7; or (ii) SNP1 genotype A/G or AA, or T/C or T/T in the complement of the SEQ ID NO: 6; and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7, wherein SNP2 is position X of SEQ ID NO. 7 identified by rs317972, wherein the SEQ ID NO. 7 is a portion of genomic nucleic acid sequence of interleukin 1 receptor antagonist (IL-1RN).

Further disclosed is a method for treating a human subject with a cartilage disorder, comprising (a) assaying a biological sample of a subject who is diagnosed as having a cartilage disorder for at least the following two SNP loci: (i) SNP1, and (ii) SNP2; and (b) administering a treatment regimen comprising a composition comprising an effective amount of an FGF-18 compound to the subject if one of the following conditions is detected: (i) SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6; and SNP2 genotype T/C or CC, or A/G or GG in the complement of the SEQ ID NO: 7; or (ii) SNP1 genotype A/G or AA, or T/C or T/T in the complement of the SEQ ID NO: 6; and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7.

Alternatively, the method for treating a human subject with a cartilage disorder comprises the steps of: (a) assaying a biological sample of a subject who is diagnosed as having a cartilage disorder for at least the following two SNP loci: (i) SNP1 and (ii) SNP2; and (b) administering a treatment regimen comprising a composition comprising an effective amount of an FGF-18 compound to the subject if SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6 and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7 is not detected.

In yet another alternative, the method for selecting a subject having a cartilage disorder, wherein said cartilage disorder is susceptible to treatment with an FGF-18 compound, comprises:

(a) obtaining a biological sample from the subject with a cartilage disorder with the objective of determining whether the cartilage disorder in the subject is susceptible to treatment with said FGF-18 compound;

(b) contacting the biological sample with at least two oligonucleotides capable of interrogating whether or not the biological sample comprises the combination of the single nucleotide polymorphisms (SNPs) selected from (i) SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6, and SNP2 genotype T/C or CC, or A/G or GG in the complement of the SEQ ID NO: 7; or (ii) SNP1 genotype A/G or AA, or T/C or T/T in the complement of the SEQ ID NO: 6; and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7;

(c) identifying the cartilage disorder in the subject as susceptible for treatment with said FGF-18 compound when either the combination of (i) or (ii) is detected in the biological sample and identifying the cartilage disorder in the subject as poorly or non-responsive to treatment with said compound when neither (i) nor (ii) is detected in the biological sample.

Also described herein is a method for selecting a treatment regimen for a subject with a cartilage disorder, comprising: (a) obtaining a test sample from the human subject diagnosed as having depression; (b) subjecting the test sample to at least one analysis to determine parameters of at least two single nucleotide polymorphisms (SNPs), wherein the at least two SNPs comprise the following: (i) SNP1 and (ii) SNP2; (c) detecting using the SNPs, the presence of at least one condition of the following or a combination thereof: i) SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6; and SNP2 genotype T/C or CC, or A/G or GG in the complement of the SEQ ID NO: 7; or ii) SNP1 genotype A/G or AA, or T/C or T/T in the complement of the SEQ ID NO: 6; and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7; or iii) SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6 and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7; and (d) providing a result output setting forth whether at least one of said condition is detected from the test sample and when condition (i) or (ii) is detected, then selecting and optionally administering a treatment regimen comprising an FGF-18 compound to the human subject, and when condition (iii) is detected, then not selecting or administering a treatment regimen comprising said compound to the human subject.

In the above mentioned methods, and assay, the patients having the genotype A/G or A/A at IL-1RN rs9007 (SNP1) and T/C or C/C at IL-1RN rs317972 (SNP2), who are predicted to be super-sensitives, are preferably selected for an alternative therapeutic regimen in which the dose of FGF-18 to be administered is reduced compared to the normal therapeutic regimen, i.e., the regimen for a patient who is predicted to be sensitive to FGF-18 compound treatment but who does not present a risk for developing AIR events.

In another embodiment of the invention, also provided are systems (and computer readable media for computer systems) for obtaining data. Said data can be used notably for assessing suitability of a treatment with an FGF-18 compound in a subject, for assessing the subject's risk of developing AIR when treated with an FGF-18 compound, or monitoring treatment efficacy of a subject with an FGF-18 compound. Said systems can be used during clinical trials, when a treatment with an FGF-18 compound has to be envisaged or when a treatment with said compound is already ongoing.

Therefore, an embodiment of the present invention includes a computer system for obtaining data from at least one test sample obtained from at least one subject with a cartilage disorder, the system comprising: (a) at least one determination module configured to receive said at least one test sample and perform at least one analysis on said at least one test sample to determine the presence or absence of the following conditions: (i) SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6, and SNP2 genotype T/C or CC, or A/G or GG in the complement of the SEQ ID NO: 7 or (ii) SNP1 genotype A/G or AA, or T/C or T/T in the complement of the SEQ ID NO: 6; and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7; or (iii) SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6, and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7; (b) at least one storage device configured to store data output from said determination module; and (c) at least one display module for displaying content based in part on the data output from said determination module, wherein the content comprises a signal indicative of the presence of at least one of these conditions, and optionally the absence of any one of these conditions.

Also described is a computer system for obtaining data from at least one test sample obtained from at least one subject, the system comprising: (a) a determination module configured to receive said at least one test sample and perform at least one genotyping analysis on said at least one test sample to determine the genotypes of at least two loci, wherein said at least two loci comprise: (i) SNP1 and (ii) SNP2; (b) a storage device configured to store output data from said determination module; (c) a computing module comprising specifically-programmed instructions to determine from the output data the presence of any of the combinations of polymorphisms selected from the following: i) SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6; and SNP2 genotype T/C or CC, or A/G or GG in the complement of the SEQ ID NO: 7; or ii) SNP1 genotype A/G or AA, or T/C or T/T in the complement of the SEQ ID NO: 6; and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7; or iii) SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6 and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7; and (d) a display module for displaying content based in part on the data output from said computing module, wherein the content comprises a signal indicative of the presence of the combination (i), (ii), or (iii) of the SNPs, and optionally the absence of any one or more or the combinations (i), (ii), and (iii) of the SNPs.

The computer readable medium can have computer readable instructions recorded thereon to define software modules for implementing a method on a computer. In such a case, said computer readable storage medium may comprise: (a) instructions for comparing the data stored on a storage device with reference data to provide a comparison result, wherein the comparison identifies the presence or absence of at least one of the following conditions: (i) SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6, and SNP2 genotype T/C or CC, or A/G or GG in the complement of the SEQ ID NO: 7, or (ii) SNP1 genotype A/G or AA, or T/C or T/T in the complement of the SEQ ID NO: 6; and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7; or (iii) SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6, and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7; and (b) instructions for displaying content based in part on the data output from said determination module, wherein the content comprises a signal indicative of the presence of at least one of the conditions, and optionally the absence of one or more of the conditions.

The computer readable storage media can be any available tangible media that can be accessed by a computer. Computer readable storage media include volatile and nonvolatile, removable and non-removable tangible media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer readable storage media include, but are not limited to, RAM (random access memory), ROM (read only memory), EPROM (erasable programmable read only memory), EEPROM (electrically erasable programmable read only memory), flash memory or other memory technology, CD-ROM (compact disc read only memory), DVDs (digital versatile disks) or other optical storage media, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage media, other types of volatile and non-volatile memory, and any other tangible medium which can be used to store the desired information and which can accessed by a computer including and any suitable combination of the foregoing.

Computer-readable data embodied on one or more computer-readable media may define instructions, for example, as part of one or more programs that, as a result of being executed by a computer, instruct the computer to perform one or more of the functions described herein, and/or various embodiments, variations and combinations thereof. Such instructions may be written in any of a plurality of programming languages, for example, Java, J#, Visual Basic, C, C#, C++, Fortran, Pascal, Eiffel, Basic, COBOL assembly language, and the like, or any of a variety of combinations thereof. The computer-readable media on which such instructions are embodied may reside on one or more of the components of either a system, or a computer readable storage medium described herein, or may be distributed across one or more of such components.

The computer-readable media may be transportable such that the instructions stored thereon can be loaded onto any computer resource to implement the aspects of the present invention discussed herein.

The information determined in the determination module can be read by the storage device. The storage device is adapted or configured for having recorded thereon expression level or protein level information. Such information may be provided in digital form that can be transmitted and read electronically, e.g., via the Internet, on diskette, via USB (universal serial bus) or via any other suitable mode of communication.

In the context of the present invention as a whole, e.g., in the context of any one of the methods, uses, assays or kits according to the present invention, the preferred FGF-18 compound is a truncated FGF-18, such as sprifermin, and the preferred cartilage disorder is selected from the group consisting of osteoarthritis, cartilage injury, fractures affecting joint cartilage or surgical procedures with impact on joint cartilage, such as microfracture.

It is to be understood that in the context of the present invention as a whole, e.g., of any one of the methods, uses, assays, computer systems or kits according to the present invention, before determining the genotype at one locus, it is necessary to obtain a nucleic acid sample (or a test sample) of a subject, for instance by blood or saliva collection. Preferably, the nucleic acid sample is a DNA sample.

An individual afflicted with a cartilage disorder and to be tested and/or treated according to any of the methods, uses, assays, kits and other computer systems described herein is a human subject that is a candidate for treatment with an FGF-18 compound, such as sprifermin. In a preferred embodiment, the individual has been diagnosed with a cartilage disorder, or exhibits a symptom of a cartilage disorder.

It is also to be understand that in the context of the invention as a whole, determination can be performed in the complementary sequence of IL1-RN rs9005 and IL1-RN rs315952. It thus follows that according to the present invention as a whole, e.g., in the context of any one of the methods, uses, assays, computer systems or kits according to the present invention, the presence of the genotype C/C on the complementary sequence to IL-1RN rs9005 and A/A on the complementary sequence of IL-1RN rs315952 is predictive of no response or low response (i.e., non-sensitivity) to treatment with an FGF-18 compound. On the contrary, the presence of the genotype T/C or T/T on the complementary sequence at IL-1RN rs9005 and A/G or G/G on the complementary sequence of IL-1RN rs315952 is predictive of high response (high-sensitivity) to treatment with an FGF-18 compound. Said genotype will also be a marker of likelihood for a patient of developing AIRs events when treated with said FGF-18 compound. The other genotypes at these loci are predictive of intermediate sensitivity (i.e., C/C in the complement of IL-1RN rs9005 and A/G or G/G in the complement of IL-1RN rs315952 or T/C or T/T in the complement of IL-1RN rs9005 and A/A in the complement of IL-1RN 315952).

In a further embodiment, the present invention encompasses a kit comprising means for performing the methods described above and instructions for use. In particular, the kit comprises at least a couple of specific primers or probes for detecting the presence or absence of the alleles. Preferably, it comprises two couples of specific primers or probes for genotyping the alleles at loci IL-1RN rs9005 and IL-1RN rs315952.

The kit may comprise an oligonucleotide array affixed with a plurality of oligonucleotide probes that interrogate no more than 20 single nucleotide polymorphisms (SNPs), said SNPs comprising: (i) SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6, and SNP2 genotype T/C or CC, or A/G or GG in the complement of the SEQ ID NO: 7; or (ii) SNP1 genotype A/G or AA, or T/C or T/T in the complement of the SEQ ID NO: 6 and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7; or (iii) SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6, and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7; an optional container containing a detectable label to be conjugated to a nucleotide molecule derived from a test sample of a subject diagnosed as having a cartilage disorder; and at least one reagent.

Alternatively, the oligonucleotide array affixed with a plurality of oligonucleotide probes interrogates no more than 17 single nucleotide polymorphisms (SNPs), no more than 10 single nucleotide polymorphisms (SNPs) or no more than 7 single nucleotide polymorphisms (SNPs).

Also described in the context of this invention is a kit comprising: a plurality of oligonucleotide primers or sets of primers that each bind to interrogate no more than one specific allele of no more than 20 single nucleotide polymorphisms (SNPs), wherein each subset of oligonucleotide primers that bind to a specific allele of an SNP is labeled with a distinct reporter, and wherein said SNPs comprise the following SNPs: i) SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6, and SNP2 genotype T/C or CC, or A/G or GG in the complement of the SEQ ID NO: 7; or ii) SNP1 genotype A/G or AA, or T/C or T/T in the complement of the SEQ ID NO: 6 and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7; or iii) SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6, and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7; and at least one reagent.

Alternatively, the plurality of oligonucleotide primers or sets of primers that each bind to interrogate no more than one specific allele of no more than 17 single nucleotide polymorphisms (SNPs), or no more than one specific allele of no more than 10 single nucleotide polymorphisms (SNPs) or no more than one specific allele of no more than 7 single nucleotide polymorphisms (SNPs).

In a further embodiment, the present invention discloses a kit for selecting a treatment regimen for a subject with a cartilage disorder, comprising at least one reagent for determining, in a test sample of a human subject diagnosed as having a cartilage disorder, the presence or absence of the following SNPs: i) SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6, and SNP2 genotype T/C or CC, or A/G or GG in the complement of the SEQ ID NO: 7; or ii) SNP1 genotype A/G or AA, or T/C or T/T in the complement of the SEQ ID NO: 6 and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7; or iii) SNP1 genotype G/G, or C/C in the complement of the SEQ ID NO: 6 and SNP2 genotype T/T, or A/A in the complement of the SEQ ID NO: 7.

In some embodiments, the oligonucleotides in the kit are either allele-specific probes or allele-specific primers. In other embodiments, the kit comprises primer-extension oligonucleotides. In still further embodiments, the set of oligonucleotides is a combination of allele-specific probes, allele-specific primers, or primer-extension oligonucleotides.

The composition and length of each oligonucleotide in a kit of the invention will depend on the nature of the genomic region containing the genetic marker of the invention as well as the type of assay to be performed with the oligonucleotide and is readily determined by the skilled artisan. For example, the polynucleotide to be used in the assay may constitute an amplification product, and thus the required specificity of the oligonucleotide is with respect to hybridization to the target region in the amplification product rather than in genomic DNA isolated from the individual.

In preferred embodiments, each oligonucleotide in the kit is a perfect complement of its target region. An oligonucleotide is said to be a “perfect” or “complete” complement of another nucleic acid molecule if every nucleotide of one of the molecules is complementary to the nucleotide at the corresponding position of the other molecule. While perfectly complementary oligonucleotides are preferred for detecting polymorphisms, departures from complete complementarity are contemplated where such departures do not prevent the molecule from specifically hybridizing to the target region as defined above. For example, an oligonucleotide primer may have a non-complementary fragment at its 5′ end, with the remainder of the primer being completely complementary to the target region. Alternatively, non-complementary nucleotides may be interspersed into the probe or primer as long as the resulting probe or primer is still capable of specifically hybridizing to the target region.

In some preferred embodiments, each oligonucleotide in the kit specifically hybridizes to its target region under stringent hybridization conditions. Stringent hybridization conditions are sequence-dependent and vary depending on the circumstances. Generally, stringent conditions are selected to be about 5° C. lower than the thermal melting point (T_(m)) for the specific sequence at a defined ionic strength and pH. The T, is the temperature (under defined ionic strength, pH, and nucleic acid concentration) at which 50% of the probes complementary to the target sequence hybridize to the target sequence at equilibrium. As the target sequences are generally present in excess, at T_(m), 50% of the probes are occupied at equilibrium. Typically, stringent conditions include a salt concentration of at least about 0.01 to 1.0 M Na ion concentration (or other salts) at pH 7.0 to 8.3 and the temperature is at least about 25° C. for short oligonucleotide probes (e.g., 10 to 50 nucleotides). Stringent conditions can also be achieved with the addition of destabilizing agents such as formamide. For example, conditions of 5×SSPE (750 mM NaCl, 50 mM Na Phosphate, 5 mM EDTA, pH 7.4) and a temperature of 25-30° C. are suitable for allele-specific probe hybridizations.

The oligonucleotides in kits of the invention may be comprised of any phosphorylation state of ribonucleotides, deoxyribonucleotides, and acyclic nucleotide derivatives, and other functionally equivalent derivatives. Alternatively, the oligonucleotides may have a phosphate-free backbone, which may be comprised of linkages such as carboxymethyl, acetamidate, carbamate, polyamide [peptide nucleic acid (PNA)] and the like. The oligonucleotides may be prepared by chemical synthesis using any suitable methodology known in the art, or may be derived from a biological sample, for example, by restriction digestion. The oligonucleotides may contain a detectable label, according to any technique known in the art, including use of radiolabels, fluorescent labels, enzymatic labels, proteins, haptens, antibodies, sequence tags and the like. The oligonucleotides in the kit may be manufactured and marketed as analyte specific reagents (ASRs) or may constitute components of an approved diagnostic device.

In other preferred embodiments, the kit includes an instruction manual that describes the various ways the kit may be used to detect the presence or absence of a genetic marker of the invention.

In a preferred embodiment, the set of oligonucleotides in the kit are allele-specific oligonucleotides. As used herein, the term allele-specific oligonucleotide (ASO) means an oligonucleotide that is able, under sufficiently stringent conditions, to hybridize specifically to one allele of a genetic marker, at a target region containing the genetic marker, while not hybridizing to the same region containing a different allele. As understood by the skilled artisan, allele-specificity will depend upon a variety of readily optimized stringency conditions, including salt and formamide concentrations, as well as temperatures for both the hybridization and washing steps.

Typically, an ASO will be perfectly complementary to one allele while containing a single mismatch for another allele. In ASO probes, the single mismatch is preferably within a central position of the oligonucleotide probe as it aligns with the genetic marker in the target region (e.g., approximately the 7th or 8th position in a 15mer, the 8th or 9th position in a 16mer, and the 10th or 11th position in a 20mer). The single mismatch in ASO primers is located at the 3′ terminal nucleotide, or preferably at the 3′ penultimate nucleotide. ASO probes and primers hybridizing to either the coding or non-coding strand are contemplated by the invention.

In other preferred embodiments, the kit comprises a pair of allele-specific oligonucleotides for a genetic marker of the invention to be assayed, with one member of the pair being specific for one allele and the other member being specific for another allele. In such embodiments, the oligonucleotides in the pair may have different lengths or have different detectable labels to allow the user of the kit to determine which allele-specific oligonucleotide has specifically hybridized to the target region, and thus determine which allele is present in the individual at the assayed marker locus.

In still other preferred embodiments, the oligonucleotides in the kit are primer-extension oligonucleotides. Termination mixes for polymerase-mediated extension from any of these oligonucleotides are chosen to terminate extension of the oligonucleotide at the genetic marker of interest, or one base thereafter, depending on the alternative nucleotides present at the marker locus.

The methods and kits according to the present invention are useful in clinical diagnostic applications. However, as used herein, the term “diagnostic” is not limited to clinical or medical uses, and the diagnostic methods and kits of the invention claimed herein are also useful in any research application, and during clinical trials, for which it is desirable to test a subject for the presence or absence of any genetic marker described herein.

In the context of the invention, the presence or absence of a particular allele or pair of alleles at the locus of a genetic marker of the invention in an individual may be detected by any technique known per se to the skilled artisan, including sequencing, pyrosequencing, selective hybridization, selective amplification and/or mass spectrometry including matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). In a particular embodiment, the alteration is detected by selective nucleic acid amplification using one or several specific primers. The alteration is detected by selective hybridization using one or several specific probes.

Further techniques include gel electrophoresis-based genotyping methods such as PCR coupled with restriction fragment length polymorphism (RFLP) analysis, multiplex PCR, oligonucleotide ligation assay, and minisequencing; fluorescent dye-based genotyping technologies such as oligonucleotide ligation assay, pyrosequencing, single-base extension with fluorescence detection, homogeneous solution hybridization such as TaqMan, and molecular beacon genotyping; sequencing-based technologies such as Sanger sequencing and next-generation sequencing platforms; rolling circle amplification and Invader assays as well as DNA chip-based microarray and mass spectrometry genotyping technologies. Protein expression analysis methods are known in the art and include 2-dimensional gel electrophoresis, mass spectrometry and antibody microarrays. Sequencing can be carried out using techniques well known in the art, e.g., using automatic sequencers. The sequencing may be performed on the complete gene or, more preferably, on specific domains thereof, typically those known or suspected to carry deleterious mutations or other alterations. Amplification may be performed according to various techniques known in the art, such as by polymerase chain reaction (PCR), ligase chain reaction (LCR) and strand displacement amplification (SDA). These techniques can be performed using commercially available reagents and protocols. A preferred technique is allele-specific PCR.

Other embodiments of the invention within the scope of the claims herein will be apparent to one skilled in the art from consideration of the specification or practice of the invention as disclosed herein. It is intended that the specification, together with the examples, be considered exemplary only, with the scope and spirit of the invention being indicated by the claims that follow the examples.

DESCRIPTION OF THE FIGURES

General notes: In the figures, 1) the terms TT, CC, GG or AA are to be understood as being T/T, C/C, G/G or A/A, and 2) the term CTA is to be understood as C-T-A.

FIG. 1: Organization of the IL1R1-IL1A-IL1B-IL1RN gene cluster. Both rs315952 and rs9005 are located in the last IL1RN exon. Although there is only 1107 bp between them, these SNPs are not inherited together (i.e., not in linkage disequilibrium). IL1RN-rs9005 is within the 3′ UTR region and overlaps both a transcription factor (ChIP-seq sequence: FOSL2) and a DNAse cluster (regulatory regions and promoter tend to be DNAse sensitive). IL1RN-rs315952 is a coding silent SNP (i.e., does not lead to an amino acid change).

FIG. 2: Stratification of the patients as a function of presence or absence (from at least one copy) of the C-T-A haplotype. The Y axis shows change at Week 52 in total cartilage volume (unit: mm³). Each point corresponds to a subject; a circle indicates a subject without AIR while a cross indicates a subject with AIRs. Indicated p-value was obtained from a non-parametric univariate test (ranksum test).

FIG. 3: Stratification of the patients as a function of presence or absence (from at least one copy) of the C-T-A haplotype. The Y axis shows change at Week 52 in WOMAC total score. Each point corresponds to a subject; a circle indicates a subject without AIR while a cross indicates a subject with AIRs. Indicated p-value was obtained from a non-parametric univariate test (ranksum test).

FIG. 4: Change in total cartilage volume (mm³) at Week 52 stratified by dose regimen and stratified by their genotype at both rs315952 and rs9005. Each point corresponds to a subject; a circle indicates a subject without AIR while a cross indicates a subject with AIRs. MRI data from the MAD010 cohort showed aberrant variability and were not included in any analyses.

FIG. 5: Change in WOMAC total score at Week 52 stratified by dose regimen and stratified by their genotype at both rs315952 and rs9005. Each point corresponds to a subject; a circle indicates a subject without AIR while a cross indicates a subject with AIRs.

FIG. 6: Stratification of the patients as a function of presence or absence of the ‘rs9005 G/G rs315952 T/T’ genotype. The Y axis shows absolute WOMAC total score at baseline. Each point corresponds to a subject; a circle indicates a subject with Kellgren-Lawrence grade equal to 2 while a cross indicates a subject with Kellgren-Lawrence grade equal to 3. Indicated p-value was obtained from a non-parametric univariate test (ranksum test).

FIG. 7: Stratification of the patients as a function of presence or absence of the ‘rs9005 A carriers rs315952 C carriers’ genotype. The Y axis shows absolute WOMAC total score at baseline. Each point corresponds to a subject; a circle indicates a subject with Kellgren-Lawrence grade equal to 2 while a cross indicates a subject with Kellgren-Lawrence grade equal to 3. Indicated p-value was obtained from a non-parametric univariate test (ranksum test).

FIG. 8: Stratification of the patients as a function of presence or absence of the ‘rs9005 G/G rs315952 T/T’ genotype. The Y axis shows absolute total cartilage volume (mm³) at baseline. Each point corresponds to a subject; a circle indicates a subject with Kellgren-Lawrence grade equal to 2 while a cross indicates a subject with Kellgren-Lawrence grade equal to 3. Indicated p-value was obtained from a non-parametric univariate test (ranksum test).

FIG. 9: Stratification of the patients as a function of presence or absence of the ‘rs9005 A carriers rs315952 C carriers’ genotype. The Y axis shows absolute total cartilage volume (mm³) at baseline. Each point corresponds to a subject; a circle indicates a subject with Kellgren-Lawrence grade equal to 2 while a cross indicates a subject with Kellgren-Lawrence grade equal to 3. Indicated p-value was obtained from a non-parametric univariate test (ranksum test).

FIG. 10: Change from baseline in WOMAC total score for all subjects irrespective of their genotypes. Lines correspond to the mean change from baseline and error bars correspond to standard error of mean.

FIG. 11: Change from baseline in WOMAC total score for subjects identified as sensitives or super-sensitives based on their rs9005 and rs315952 genotypes. The ‘treated’ group corresponds to subjects from the MAD100 cohort having the genotype identifying sensitive subjects. Subjects from the MAD030 cohort having the genotype identifying super-sensitive subjects are also included in this ‘treated’ group. The ‘placebo’ group includes placebo subjects with genotypes corresponding to either the sensitives or to the super-sensitives. Lines correspond to the mean change from baseline and error bars correspond to standard error of mean.

FIG. 12: Change from baseline in WOMAC total score for subjects having the genotype corresponding to the non-sensitives. Lines correspond to the mean change from baseline and error bars correspond to standard error of mean.

FIG. 13: Change from baseline in total cartilage volume (mm³) for all subjects irrespective of their genotypes. Lines correspond to the mean change from baseline and error bars correspond to standard error of mean. MRI data from the MAD010 cohort showed aberrant variability and were not included in any analyses.

FIG. 14: Change from baseline in total cartilage volume (mm³) for subjects identified as sensitives or super-sensitives based on their rs9005 and rs315952 genotypes. The ‘treated’ group corresponds to subjects from the MAD100 cohort having the genotype identifying sensitives. Subjects from the MAD030 cohort having the genotype identifying super-sensitives are also included in this ‘treated’ group. The ‘placebo’ group includes placebo subjects with genotypes corresponding to either the sensitives or to the super-sensitives. Lines correspond to the mean change from baseline and error bars correspond to standard error of mean. MRI data from the MAD010 cohort did not pass quality control and were not included in any analyses.

FIG. 15: Change from baseline in total cartilage volume (mm³) for subjects having the genotype corresponding to the non-sensitives. Lines correspond to the mean change from baseline and error bars correspond to standard error of mean. MRI data from the MAD010 cohort showed aberrant variability and were not included in any analyses.

FIGS. 16(a)-(h): Set out the full length amino acid and nucleic acid sequences corresponding to the “SEQ ID NOs” referenced in the instant patent application.

DESCRIPTION OF THE SEQUENCES

SEQ ID NO: 1: Amino acid sequence of the native human FGF-18.

SEQ ID NO: 2: Amino acid sequence of the recombinant truncated FGF-18 (trFGF-18).

SEQ ID NO: 3: IL1RN gene.

SEQ ID NO: 4: IL1RN rs9005 locus.

SEQ ID NO: 5: IL1RN rs315952 locus.

SEQ ID NO: 6: Specific region from IL1RN rs9005 locus (corresponding to nucleotide 415 to nucleotide 466 of SEQ ID NO: 4), wherein N is A or G.

SEQ ID NO: 7: Specific region from IL1RN rs315952 locus (corresponding to nucleotide 415 to nucleotide 466 of SEQ ID NO: 5), wherein N is C or T.

SEQ ID NO: 8: rs315952 primer 1.

SEQ ID NO: 9: rs315952 primer 2.

SEQ ID NO: 10: rs9005 primer 1.

SEQ ID NO: 11: rs9005 primer 2.

EXAMPLES 1. Genotyping Background:

The level of cartilage volume growth and the associated risks of adverse events in response to sprifermin treatment in cartilage disorders, such as osteoarthritis, cartilage injury, fractures affecting joint cartilage or surgical procedures with impact on joint cartilage (e.g., microfracture), may each be associated with a specific genetic variation in one or several genes. In the present study, the search for associations between genes containing variations and disease or response to treatment was focused on candidate genes that were selected based on the physiological role of the proteins they encode and their potential implication in the cartilage disorders, or in the response to sprifermin treatment. The list of selected candidate SNPs that have been tested is given in Table 1.

Response to sprifermin treatment was measured by change in cartilage volume from baseline 1 year after the beginning of treatment with sprifermin.

It is noted that candidate and whole genome scan SNP markers were not kept for further analysis if any of the following criteria were met:

-   -   Rare variant SNP in the PGx ITT population: Minor Allele         Frequency (MAF)<10% for both candidate SNP and whole genome scan         SNPs.     -   Questionable genotyping quality, as measured by a high rate         (≥5%) of missing data.     -   Significant deviation from the Hardy-Weinberg equilibrium         (Bonferroni adjusted p value less than 5% for candidate SNPs or         FDR (i.e., Benjamini-Hochberg adjusted p value) less than 20%         for whole genome scan SNPs).     -   Subjects with gender discrepancy between the clinical database         and the predicted gender from whole genome scan SNP data         (chromosome X) are excluded.

The candidate genes selected have been previously implicated in cartilage disorders, such as osteoarthritis. The purpose of the study was to investigate whether the level of response, i.e., cartilage volume growth and/or occurrence of adverse events in response to sprifermin treatment in cartilage disorder, is correlated with a specific DNA variant or pattern of variants. The existence of such a correlation would indicate that either the gene(s) carrying the identified variant(s) or one or more genes lying in the vicinity of the variants may be susceptibility gene(s).

2. Materials and Methods 2.1. FGF-18 Compound

The FGF-18 compound used as a treatment in the present examples is sprifermin. It is a truncated form of FGF-18, as defined in the section “definitions”.

2.2. Sample Reception and Double Coding

Blood samples were received from patients participating in study 28980 (A randomized, double blind, placebo-controlled, multicenter, single and multiple ascending dose study of sprifermin, administered intra-articularly in patients with primary osteoarthritis of the knee who are not expected to require knee surgery within one year).

In order to comply with the Pharmacogenomics (PGx) Informed Consent Form (ICF), which covered the DNA analysis, all samples were double-coded by the Biobank (Merck Serono, Geneva) to ensure an additional level of subject anonymity. The Biobank provided the Biomarker Data Management group with the double key coding as a flat file containing both the PGx ID and the Subject ID for each subject. Additional verifications were performed to ensure that no DNA analyses are performed on subjects who did not consent to the PGx study.

2.3. DNA Sample Extraction, Amplification, Fragmentation and Labeling

The analysis was performed on DNA extracted from blood. A total of 140 blood samples were received. Out of these 140, 3 samples were destroyed by the genomic laboratory as the patients withdrew their consent during the course of study, resulting in 137 DNAs analyzed corresponding to 137 patients. Thus 137 patients were genotyped and eligible for the association studies.

Genomic DNA was extracted from EDTA blood samples using a Qiagen extraction kit (QIAamp DNA Blood Maxi Kit). After extraction, measures of sample absorbance at wavelengths of 260 nm and 280 nm using a spectrophotometer and electrophoresis on agarose gels were performed to estimate the quality and quantity of genomic DNA samples.

For each plate, genomic DNA samples were digested with Nspl and Styl restriction endonucleases, ligated with specific adaptors (Nsp or Sty), processed in parallel until the Polymerase Chain Reactions (PCR). PCR amplified the product of ligation in triplicate for Styl reactions and in quadruplicate for Nspl reactions, to product a large efficiency. All the PCR products were pooled, purified, quantified, fragmented and labeled.

The PCR amplification step was evaluated using electrophoresis agarose gel. The DNA quantification step was measured using a spectrophotometer. The DNA fragmentation step was evaluated using electrophoresis agarose gel. The average DNA fragment size should be lower than 180 bp.

2.4. DNA Microarray Technology (Whole Genome Scan)

The Affymetrix Genome Wide SNP 6.0 Assays were used to perform the Whole Genome Scan (hypothesis free approach). The Affymetrix technology is based on a DNA chip allowing the genotyping of approximately 906 600 single nucleotide polymorphisms (SNPs) per patient. SNPs are randomly distributed in all the chromosomes and are used as tagging markers of the corresponding genomic area. The details of process and protocol followed the PGX Affymetrix wide-genome SNP 5.0/6.0 technology.

For each sample, the labeled product was hybridized into the Affymetrix Genome Wide SNP 6.0 GeneChip. Two lots of chips were used for both sets.

After hybridization and staining, the Affymetrix Gene Chips were scanned to create image data (DAT) files. After that, AGCC Software automatically aligned a grid on the DAT files and computed the Cell Intensity data (CEL) file. Afterwards the CEL data passed on to Genotyping Console software that generated Probe Analysis (CHP) data.

Analysis quality control (QC) was performed using Genotyping Console Software assessing the Dynamic Model QC (DM) call rate analysis of a subset of 3022 SNPs following chip scanning. DM call rates measure the consistency of intensities within each SNP, with four possible genotyping states (Null, AA, AB and BB). It provides an estimate of the overall quality for a data sample prior to performing full clustering analysis. It is based on QC Call Rate.

The QC Call Rate (QC CR) is well correlated with clustering performance and is an effective single-sample metric for deciding what samples should be used in downstream clustering. The fixed threshold for Genome wide SNP6.0 arrays is >=86%. In addition to QC CR, another algorithm has been developed for SNP 6.0 arrays. This new algorithm is the Contrast QC. The contrast QC is a metric that captures the ability of an experiment to resolve SNP signals into three genotype clusters. It measures the separation of allele intensities into three clusters in “contrast space”. Contrast space is a projection of the two-dimensional allele intensity space into an informative single dimension. The default threshold is >=0.4 for each sample. The results of QC are automatically displayed in the Intensity QC Table. Samples which pass the QC threshold (call rate >86% and contrast QC>0.4) are noted as “bound in”, and those which did not pass the QC (call rate <86% or contrast QC<0.4) are noted as “bound out”. The genomic DNA samples of the study passed all QC.

2.5. TaqMan SNP Genotyping (Candidate Gene)

TaqMan SNP Genotyping was performed to detect selected markers based on literature information. A total of 19 SNPs distributed onto 8 candidate genes were selected and carried out in two periods (see Tables 2a and 2b). In a TAQMAN SNP Genotyping assay, two locus-specific PCR primers surrounding the SNP are used to amplify a fragment of about 100 bp. Two allele-specific probes are then hybridized to their specific SNP sequence (see for instance Table 3). Each probe was labeled at its 5′ extremity with either a fluorescent reporter dye (FAM) or VIC reporter dye. Each probe also has a non-fluorescent quencher dye, MGB, at the 3′ end. In each PCR cycle, if the target sequence of the allele-specific probe is amplified, the probe will hybridize to the DNA during the annealing step and extend. When the DNA polymerase comes into contact with this hybridized probe, the reporter dye of the probe is cleaved from the probe, leaving the quencher dye behind. In each cycle of the PCR, cleavage of the reporter dyes from one or both of the allele-specific probes causes an exponential increase in the fluorescent intensity. At PCR completion, the total fluorescence of each sample is read on the ABI 9700 (384-well format). If fluorescence is observed from only one probe, the sample is homozygous for this allele. If fluorescence is observed from both allele-specific probes, the sample is heterozygous for both alleles. If the probe does not hybridize, the fluorescence of the dye is “quenched” or reduced by the quencher dye, and thus minimal fluorescence is observed, indicating a failed genotype.

Protocol is detailed in the datasheet of TAQMAN SNP Genotyping.

Period 1: DNA samples were genotyped with 17 TAQMAN SNP assays (see Table 2a).

Period 2: DNA samples were genotyped with 2 further TAQMAN SNP assays (see Table 2b).

For each TAQMAN SNP assay, the NTC cluster was specific and all NTCs were undetermined, the three distinct sample clusters were present and genotyping was automatically assigned and the call rate was specified to be above 85 percent.

For each of the 19 TAQMAN SNP assays in the three parts, acceptance criteria were reached.

2.6. SNP Filtering

Candidate and whole genome scan SNP markers were not kept for analysis if any of the following criteria were met:

-   -   Rare variant SNP in the PGx ITT population: Minor Allele         Frequency (MAF)<10% for both candidate SNP and whole genome scan         SNPs.     -   Questionable genotyping quality, as measured by a high rate (5%)         of missing data.     -   Significant deviation from the Hardy-Weinberg equilibrium         (Bonferroni adjusted p value less than 5% for candidate SNPs or         FDR (i.e., Benjamini-Hochberg adjusted p value) less than 20%         for whole genome scan SNPs).     -   Subjects with gender discrepancy between the clinical database         and the predicted gender from whole genome scan SNP data         (chromosome X) are excluded.

2.7. Association Tests

For association tests, genotype data were coded as presence/absence of the SNP minor allele (i.e., homozygous for major allele compared to at least one copy of the minor allele).

2.7.1. Association with Acute Inflammatory Reactions (AIRs)

In these analyses, only subjects treated with 100 mcg FGF-18 dose were used. For single marker analysis, two approaches were used: Fisher's exact test and a multivariate linear model (i.e., AIR status˜SNP+Kellgren Lawrence grade [2; 3]+Gender [Female; Male]+Age [<65; ≥65]+BMI [<30, ≥30]. In this model, significance of each term in the model was assessed with a type III anova).

2.7.2. Association with WOMAC Total Scores and Total Cartilage Volume

Association between change from baseline at week 52 (termination date), both for WOMAC total scores and total cartilage volume, was assessed using the following linear model:

Rank (change in endpoint)˜Arm [Placebos, Treated subjects e.g., with FGF-18 100 mcg dose]+genotype group+Kellgren-Lawrence grade [2; 3]+Gender [Female; Male]+Age [<65; ≥65]+BMI [<30, ≥30]. Significance of each term in the model was assessed with a type III anova and significance threshold was set at alpha=5%.

2.7.3. Association Between a Given Genotype Group and Kellgren-Lawrence Grade

To test whether a given genotype group (for, e.g., subjects with the ‘IL-1RN rs9005 G/G and IL-1RN rs315259 T/T’ genotype) had a significant enrichment or paucity in subjects with severe osteoarthritis (i.e., Kellgren-Lawrence grade 3), independent tests were performed using a Fisher's exact test and from the following contingency table:

Grade 3 Grade 2 # of subjects from a given genotype group # of subjects from the remaining genotype groups

All available subjects from any dose regimen (including placebos) were included in this analysis. P-values were computed using a two-sided test and significance was set at alpha=5%. Odds ratio and their 95% confidence intervals were also computed.

2.8. Haplotype Analyses

Genotype data from SNPs rs419598, rs315952, and rs9005 were phased (using the MACH software, version 1.0.18.c, Li Y et al., 2010) to infer presence or absence of the C-T-A haplotype in subjects. The following MACH parameters were used: “-rounds 50-states 200-phase”. Association with AIRs was tested using a Fisher's exact test (significance threshold set at alpha=5%).

2.9. Combinatorial Analyses Between Candidate SNPs

In initial association analyses (data not shown), the rs9005 SNP was found to be significantly associated with AIRs. Combinatorial analyses (i.e., epistasis) were performed to test whether IL-1RN rs9005, in combination of another SNP from a list of about 120 candidate SNPs, would be a better AIR predictor (see Table 1). Such analysis was performed using a logistic regression with the following model:

AIR status˜rs9005*another SNP+Kellgren-Lawrence grade [2; 3]+Gender [Female; Male]+Age [<65; ≥65]+BMI [<30, ≥30].

Significance of each term in the model was assessed with a type III anova. Interaction p-values were adjusted for multiple testing using the Benjamini-Hochberg procedure (Benjamini and Hochberg, 1995, J. of the Royal Statistical Society Series B(57):289) and significance threshold was set at FDR=5%. Epistasis effects were confirmed using the statistical approach described in Wrapati et al., 2011.

2.10. Performance Metrics at Predicting AIRs

Performance metrics at predicting AIRs were derived from the corresponding contingency table. These metrics included sensitivity, specificity, accuracy, precision, negative predictive value and Fl score (i.e., harmonic mean of precision and recall).

3. Results 3.1. Predictive Analyses

Combinatorial analyses identified only one combination (IL-1RN rs9005 and IL-1RN rs315259) as significantly associated with AIRs (FDR from multivariate linear model=0.0187, Fisher's exact test p-value=0.0018, odds ratio=18.82 [2.25-260.03]). Contingency table and prediction performance metrics are shown respectively in Table 5 and Table 6. The combination of rs9005 and rs315259 (Table 6) has a better performance at predicting AIRs, compared to the C-T-A haplotype (Table 8; see also contingency table in Table 7). The combination of IL-1RN rs9005 and IL-1RN rs315259 has a very strong specificity (94.44%) and negative predictive value (89.47%), i.e., these biomarkers have a very strong performance at identifying subjects that will not have AIRs. In addition, this combination reveals stratification on total cartilage volume (FIG. 4) and WOMAC total scores (FIG. 5). By contrast, the C-T-A haplotype does not allow such clinical outcome stratification (FIGS. 2 and 3). Indeed, the C-T-A haplotype did not allow stratifying subjects for change in total cartilage volume (FIG. 2) nor change in WOMAC total score (FIG. 3). Thus the C-T-A haplotype was not identified as a good predictor of the response to drug therapy, preferably an anabolic drug such as sprifermin.

3.2. Prognostic Analyses

Placebo subjects with the ‘IL-1RN rs9005 G/G and IL-1RN rs315259 T/T’ genotype were identified as having significantly higher total cartilage volume than treated subjects from the same genotype group. To follow up on this result, change in WOMAC total score and change in total cartilage volume were modeled in placebo subjects with the following formula:

Rank(change in endpoint)˜genotype group+Kellgren-Lawrence grade [2;3]+Gender[Female;Male]+Age[<65;≥65]+BMI[<30, ≥30].

No significant difference in WOMAC total score was found between subjects from the four different genotype groups (p-value=0.63, Table 10). However, significant differences were found in change in total cartilage volume (p-value=0.02, Table 9). Subjects from the ‘IL-1RN rs9005 G/G and IL-1RN rs315259 T/T’ genotype group have significantly higher total cartilage volume increase compared to subjects from the remaining genotype groups.

An independent test between the Kellgren-Lawrence grade and subjects from a given genotype group demonstrated that the ‘IL-1RN rs9005 G/G and IL-1RN rs315259 T/T’ genotype group has a significant paucity in subjects from Kellgren-Lawrence grade 3 (Fisher's exact test p-value=0.0179, Table 11). The corresponding odds ratio is 0.306 (with 95% confidence intervals [0.096, 0.885]). This demonstrates that subjects from the ‘IL-1RN rs9005 G/G and IL-1RN rs315259 T/T’ genotype group are classified with a less severe osteoarthritis condition than subjects from other genotype groups. Lending support to this result, subjects from the ‘IL-1RN rs9005 G/G and IL-1RN rs315259 T/T’ genotype group have marginally smaller baseline WOMAC total scores than subjects from other genotype groups (ranksum p-value=0.0927, see FIG. 6). In addition, subjects from the ‘IL-1RN rs9005 G/G and IL-1RN rs315259 T/T’ genotype group have significantly higher baseline total cartilage volume than subjects from other genotype groups (ranksum p-value=0.0204, see FIG. 8).

Interestingly, there was no difference in the proportion of subjects with Kellgren-Lawrence grade 3 between the ‘IL-1RN rs9005 A carriers and IL-1RN rs315259 C carriers’ genotype group (aka super-sensitives) and subjects from the remaining genotype groups (Fisher's exact test p-value=0.2736, odds ratio=1.693 [0.637, 4.769], Table 12). Thus the super-sensitive group is not enriched in subjects with severe osteoarthritis conditions. This is further enforced with the fact that both baseline WOMAC total scores and baseline total cartilage volume are comparable between super-sensitive subjects and other subjects (see FIGS. 7 and 9).

Analysis with the C-T-A haplotype did not reveal a difference in the proportion of subjects with Kellgren-Lawrence grade 3 and bearing at least one copy of the C-T-A haplotype (Fisher's exact test p-value=1).

3.3. Clinical Outcome Using the Proposed Genetic Diagnostic Test

Without any genetic stratification, the clinical outcomes of the FGF-18 therapy are the following: 1) significant increase in total cartilage volume (i.e., cartilage repair) in treated subjects (MAD100) compared to placebos (p-value=0.0157); 2) marginally smaller improvement in WOMAC total scores in treated subjects (MAD100) compared to placebos (p-value=0.1044); and 3) 20% of AIRs in treated subjects. These results are summarized in Table 13 and detailed results are presented in Table 14 and Table 15. FIGS. 10 and 13 are also provided for data visualization. It is understood that FIGS. 10 to 15 do not correspond to the multivariate linear model used for the analyses. These figures are only provided to facilitate results interpretation.

The proposed diagnostic test (Table 4) aims at:

-   -   1. Identifying sensitives and treating them with the proposed         FGF-18 dose (e.g., 100 mcg)     -   2. Identifying super-sensitives and treating them with a lower         FGF-18 dose (e.g., 30 mcg), and     -   3. Identifying non-sensitives and excluding them from FGF-18         therapy.

Retrospectively, the clinical outcomes for subjects elected for FGF-18 therapy are:

-   -   1. Significant increase in total cartilage volume in treated         subjects (sensitives from MAD100 cohort+super-sensitives from         MAD030 cohort) compared to matched placebos (p-value=0.0016         Table 18, FIG. 14). Simulation studies (bootstrap) showed that         this cartilage volume improvement is significantly higher than         the improvement obtained when no diagnostic test is used         (p-value <1E-4).     -   2. Comparable improvement in WOMAC total scores between treated         subjects and placebos (p-value=0.6603, Table 17, FIG. 11).     -   3. 11.43% of AIRs in treated subjects (Table 16).

In contrast, subjects identified as non-sensitives have the following clinical outcomes:

-   -   1. Significantly lower improvement in total cartilage volume in         treated subjects (non-sensitives from MAD100 cohort) compared to         matched placebos (p-value=0.0289, Table 21). Subjects from the         MAD030 cohort had similar outcomes to subjects from the MAD100         cohort (FIG. 15). Thus none of the investigated doses showed an         improvement with respect to placebos.     -   2. Although the p-value from the multivariate linear model is         not significant (p-value=0.3068, Table 20), there is no         improvement in WOMAC total score for treated subjects (median         change=−1), while there is some improvement for placebos (median         change=−39). Subjects from the MAD010 and MAD030 cohorts had         similar outcomes to subjects from the MAD100 cohort (FIG. 12).         Thus none of the investigated doses showed an improvement with         respect to placebos.     -   3. 22.22% of AIRs in treated subjects (Table 19).

Tables

TABLE 1 List of candidate SNPs Gene/description Tested SNPs FGF-18 rs3806929, rs4073716, rs9313543, rs4076077, rs4073717, rs6555956, rs10065728, rs4620037, rs11553493 FGFR1 rs2288696, rs2978073, rs11777067, rs6983315, rs7012413, rs6996321 FGFR2 rs3135810, rs2278202, rs1649200, rs7090018, rs2912759, rs2912787, rs2981449, rs2981432, rs10736303, rs1078806, rs2981575, rs1219648, rs1219643, rs2912774, rs2162540, rs2981582, rs3135715, rs3750819, rs755793 FGFR3 rs17880763, rs17881656, rs17882190, rs17884368 FGFR4 rs442856, rs422421, rs2011077 FGFRL1 rs4647934 IL10 rs1878672, rs3024493, rs1554286, rs3024491, rs3024490 IL1A rs1304037, rs3783550, rs3783525, rs1800587 IL1B rs1143627, rs1143634, rs1143633, rs3136558 IL1RN rs9005, rs315952, rs444413, rs3181052, rs419598, rs423904, rs442710, rs447713, rs451578, rs432014, rs431726, rs452204, rs3087266, rs579543 IL6 rs1800795, rs1800797, rs1474347, rs2069840, rs1800796 marginal association with rs5934659, rs12407610, rs1344049, rs10954969, rs1522844, AIRs (from whole-genome rs2685592, rs6697273, rs887071, rs1105227, rs6846033, rs871746, scan) rs11815080, rs6949763, rs897718, rs7651624, rs6989732, rs7786717, rs10093384, rs11737974, rs3122569, rs12453065, rs1992509, rs2202731, rs6897534, rs747159, rs4342357, rs2447011, rs4770271, rs10430746, rs7032155, rs10948190, rs7073333, rs6495812, rs946120, rs1047813, rs2032790, rs3865404, rs11040899, rs1968294, rs723077 marginal association with rs12410403, rs587505, rs9902708, rs734397, rs894013, rs932241 WOMAC total score (from whole-genome scan) TNFRS1B rs1061622 VDR region rs731236, rs7975232, rs1544410

TABLE 2a Details of TaqMan SNP Id screened in period 1 NCBI Gene Symbol rs Id Assay Id alleles Assay type FGF-18 rs4073716 C__27537611_10 C/T Functionally Tested FGF-18 rs11553493 NA G/T Custom FGF-18, rs3806929 C__ 11274941_10 C/T Functionally NPM1 Tested FGFR2 rs755793 C__2414603_10 C/T Validated FGFR3 rs17881656 NA C/T Custom FGFR3, rs17880763 C__58182661_10 A/T Functionally LETM1 Tested FGFR3, rs17882190 C__58182657_10 A/G Functionally LETM1 Tested IL1B rs1143627 C__1839944_10 C/T Validated IL-6 rs1800795 hCV1839697 C/G Custom/ SNPlex system IL6, rs1800796 C__11326893_10 C/G Functionally LOC541472 Tested LETM1, rs17884368 C__58182646_10 A/G Functionally FGFR3 Tested LOC100131885, rs3750819 C__27511529_10 C/G Functionally FGFR2 Tested LOC541472, rs1800797 C__1839695_20 A/G Functionally IL6 Tested TNFRSF1B rs1061622 C__8861232_20 G/T Functionally Tested VDR rs7975232 C__28977635_10 A/C Functionally Tested VDR rs731236 C__2404008_10 C/T Functionally Tested VDR rs1544410 C__8716062_10 A/G Validated

TABLE 2b Details of TaqMan SNP Id screened in period 2 Gene NCBI Symbol rs Id Assay Id alleles Assay type IL1RN rs9005 C__3133528_10 A/G Functionally Tested IL1RN rs315952 C__ 11512470_10 C/T Validated

TABLE 3 Taqman primer sequences Applied SNP Biosystems Reference assay ID Primer sequences rs315952 C_11512470_10 Primer 1: GCTTCGCCTTCATCC GCTCAGACAG (SEQ ID NO: 8) or complementary sequence Primer 2: GGCCCCACCACCAGT TTTGAGTCTG (SEQ ID NO: 9) or complementary sequence rs9005 C_3133528_10 Primer 1: TGTGCCTCTGCCTGT CTCCCCCACC (SEQ ID NO: 10) or complementary sequence Primer 2: GGCTGGGAGCTCTGC AGAGCAGGAA (SEQ ID NO: 11) or complementary sequence

TABLE 4 Identified genotype categories in the Multiple Ascending Dose cohort (100 mcg) rs9005 (A/G) G/G A carriers rs315952 T/T group A: group B: (T/C) non-sensitives Sensitives (20% of MAD100) (27% of MAD100) C carriers group C: group D: Sensitives super-sensitives (38% of MAD100) (15% of MAD100)

TABLE 5 Contingency table: AIR predictions based on rs9005 and rs315952 genotypes with subjects from the FGF-18 MAD100 arm (n = 45) True AIR status Subjects Subjects with AIRs without AIRs Predicted status Predicted with AIRs 5 2 Predicted without AIRs 4 34

TABLE 6 Performance at predicting AIRs based on rs9005 and rs315952 genotypes with subjects from the FGF-18 MAD100 arm (n = 45) Performance metrics value Sensitivity 55.56% Accuracy 86.67% Specificity 94.44% Precision 71.43% Negative predictive value 89.47% Sensitivity and precision (F1 score) 62.50%

TABLE 7 Contingency table: AIR predictions based on presence/absence of the C-T-A haplotype with subjects from the FGF-18 MAD100 arm (n = 48) True AIR status Subjects Subjects with AIRs without AIRs Predicted Predicted with AIRs 6 7 status Predicted without AIRs 4 31

TABLE 8 Performance at predicting AIRs based on presence/absence of the C-T-A haplotype with subjects from the FGF-18 MAD100 arm (n = 48) Performance metrics value Sensitivity    60% Accuracy 77.08% Specificity 81.58% Precision 46.15% Negative predictive value 88.57% Sensitivity and precision (F1 score) 52.17%

TABLE 9 Multivariate linear modeling for change in total cartilage volume with placebo subjects only regression Standard model term coefficient Error Z-score p-value Intercept 78.44 23.68 3.31 0.0035 group 83.11 33.85 2.46 0.0234 [B-C-D; A only] Kellgren-Lawrence −12.93 22.36 −0.58 0.5695 grade [2; 3] Age [<65; >=65] −15.83 20.86 -0.76 0.4569 BMI [<30; >=30] 4.02 21.61 0.19 0.8545 Gender [Female; Male] −15.01 20.31 −0.74 0.4683

TABLE 10 Multivariate linear modeling for change in WOMAC total score with placebo subjects only regression Standard model term coefficient Error Z-score p-value Intercept 63.76 20.40 3.13 0.0051 group −13.98 28.71 −0.49 0.6313 [B-C-D; A only] Kellgren-Lawrence −25.47 18.83 −1.35 0.1906 grade [2; 3] Age [<65; >=65] 0.34 17.66 0.02 0.9847 BMI [<30; >=30] 46.97 18.08 2.60 0.0168 Gender 29.74 17.01 1.75 0.0950 [Female; Male]

TABLE 11 Contingency table: Kellgren-Lawrence grade (3 or 2) based on presence/absence of the ‘rs9005 G/G rs315952 TT’ genotype-Analysis was performed using all subjects from all dose regimens (including placebos). Fisher's exact test p-value is 0.0179, odds ratio is 0.306 with 95% confidence interval [0.096, 0.885]. genotype Grade 3 Grade 2 rs9005 G/G rs315952 T/T 7 15 other 60 39

TABLE 12 Contingency table: Kellgren-Lawrence grade (3 or 2) based on presence/absence of the ‘rs9005 A carriers rs315952 C carriers’ genotype-Analysis was performed using all subjects from all dose regimens (including placebos). Fisher's exact test p-value is 0.2736, odds ratio is 1.693 with 95% confidence interval [0.637, 4.769]. genotype Grade 3 Grade 2 rs9005 A carriers rs315952 C 17 9 carriers other 50 45

TABLE 13 Clinical outcome without diagnostic test (45 subjects treated with FGF-18 100 mcg and 27 placebos)-Delta corresponds to the difference between the median change in placebos and the median change in treated subjects. P-value corresponds to the p-value from a multivariate linear model adjusting for gender, age, BMI and KL grade. median change in Groups median change in treated subjects A, B, C, D placebos (MAD100) delta p-value Change in WOMAC −19 −10 9 0.1044 total score Change in total −44.68 102.25 146.93 0.0157 cartilage volume % AIRs 3.7 20 16.3 NA

TABLE 14 Multivariate linear modeling for change in WOMAC total score with all placebos and all MAD100 treated subjects LR Chi- model regression Standard p-value square p-value term coefficient Error Z-score (GLM) (anova) (anova) Intercept 59.51 14.86 4.00 0.0002 NA NA Age [<65; 11.07 12.61 0.88 0.3834 0.77 0.3802 >=65] Arm (dose 19.51 12.02 1.62 0.1091 2.64 0.1044 100 mcg) BMI [<30; 13.24 12.09 1.10 0.2774 1.20 0.2734 >=30] Gender 20.13 11.84 1.70 0.0937 2.89 0.0890 [Female; Male] Kellgren- 0.14 11.79 0.01 0.9902 0.00 0.9902 Lawrence grade [2; 3]

TABLE 15 Multivariate linear modeling for change in total cartilage volume with all placebos and all MAD100 treated subjects LR Chi- model regression Standard p-value square p-value term coefficient Error Z-score (GLM) (anova) (anova) Intercept 79.10 13.37 5.92 0.0000 NA NA Age [<65; −15.10 11.35 −1.33 0.1878 1.77 0.1832 >=65] Arm 26.12 10.81 2.42 0.0185 5.84 0.0157 [placebos; treated] BMI [<30; −14.60 10.87 −1.34 0.1841 1.80 0.1795 >=30] Gender 1.05 10.65 0.10 0.9216 0.01 0.9213 [Female; Male] Kellgren- −1.25 10.61 −0.12 0.9065 0.01 0.9061 Lawrence grade [2; 3]

TABLE 16 Clinical outcome for subjects classified as 1) sensitives (groups B and C, n = 29, treated with FGF-18 100 mcg) or 2) super-sensitives (group D, n = 6, treated with a lower FGF-18 dose: 30 mcg). 24 placebos, with genotypes from either group B, C or D, were included in the analysis-Delta corresponds to the difference between the median change in placebos and the median change in treated subjects, P-value corresponds to the p-value from a multivariate linear model adjusting for gender, age, BMI and KL grade. median change in median change treated subjects Groups B, C, D in placebos (MAD100 + MAD30) delta p-value Change in −16.5 −13 3.5 0.6603 WOMAC total score Change in total −114.91 102.25 217.16 0.0016 cartilage volume % AIRs 0 11.43 11.43 NA

TABLE 17 Multivariate linear modeling for change in WOMAC total score with subjects classified as 1) sensitives (groups B and C, n = 29, treated with FGF-18 100 mcg) or 2) super-sensitives (group D, n = 6, treated with a lower FGF-18 dose: 30 mcg). 24 placebos, with genotypes from either group B, C or D, were included in the analysis. LR Chi- model regression Standard p-value square p-value term coefficient Error Z-score (GLM) (anova) (anova) Intercept 67.09 16.25 4.13 0.0001 NA NA Age [<65; 7.23 13.33 0.54 0.5900 0.29 0.5877 >=65] Arm 5.82 13.24 0.44 0.6621 0.19 0.6603 [placebos; treated] BMI [<30; 3.87 12.82 0.30 0.7641 0.09 0.7629 >=30] Gender 16.54 13.68 1.21 0.2322 1.46 0.2268 [Female; Male] Kellgren- 6.67 13.09 0.51 0.6124 0.26 0.6103 Lawrence grade [2; 3]

TABLE 18 Multivariate linear modeling for change in total cartilage volume with subjects classified as 1) sensitives (groups B and C, n = 29, treated with FGF-18 100 mcg) or 2) super-sensitives (group D, n = 6, treated with a lower FGF-18 dose: 30 mcg). 24 placebos, with genotypes from either group B, C or D, were included in the analysis. LR Chi- model regression Standard p-value square p-value term coefficient Error Z-score (GLM) (anova) (anova) Intercept 64.94 14.46 4.49 0.0000 NA NA Age [<65; −15.89 11.86 −1.34 0.1860 1.79 0.1803 >=65] Arm 37.14 11.78 3.15 0.0027 9.94 0.0016 [placebos; treated] BMI [<30; −5.47 11.40 −0.48 0.6332 0.23 0.6312 >=30] Gender 1.14 12.18 0.09 0.9258 0.01 0.9254 [Female; Male] Kellgren- 1.27 11.65 0.11 0.9137 0.01 0.9133 Lawrence grade [2; 3]

TABLE 19 Clinical outcome for subjects classified as non-sensitives by the diagnostic test (MAD100 n = 9, MADPL n = 3)-Delta corresponds to the difference between the median change in placebos and the median change in treated subjects. P-value corresponds to the p-value from a multivariate linear model adjusting for gender, age, BMI and KL grade. median change in median change in treated subjects Group A only placebos (MAD100) delta p-value Change in WOMAC −39 −1 38 0.3068 total score Change in total 224.56 117.92 −106.64 0.0289 cartilage volume % AIRs 33.33 22.22 −11.11 NA

TABLE 20 Multivariate linear modeling for change in WOMAC total score, with subjects classified as non-sensitives by the diagnostic test (MAD100 n = 9, MADPL n = 3) LR Chi- model regression Standard p-value square p-value term coefficient Error Z-score (GLM) (anova) (anova) Intercept 38.99 40.18 0.97 0.3693 NA NA Age [<65; 1.62 45.92 0.04 0.9730 0.00 0.9718 >=65] Arm 43.10 42.18 1.02 0.3462 1.04 0.3068 [placebos; treated] BMI [<30; 18.24 38.93 0.47 0.6558 0.22 0.6393 >=30] Gender 43.01 33.47 1.29 0.2461 1.65 0.1987 [Female; Male] Kellgren- −19.53 34.44 −0.57 0.5911 0.32 0.5706 Lawrence grade [2; 3]

TABLE 21 Multivariate linear modeling for change in total cartilage volume with subjects classified as non-sensitives by the diagnostic test (MAD100 n = 9, MADPL n = 3) LR Chi- model regression Standard p-value square p-value term coefficient Error Z-score (GLM) (anova) (anova) Intercept 128.67 15.26 8.43 0.0002 NA NA Age [<65; 47.00 17.44 2.70 0.0358 7.27 0.0070 >=65] Arm −35.00 16.02 −2.19 0.0715 4.78 0.0289 [placebos; treated] BMI [<30; 30.67 14.78 2.07 0.0834 4.30 0.0380 >=30] Gender −39.00 12.71 −3.07 0.0220 9.42 0.0022 [Female; Male] Kellgren- 7.00 13.08 0.54 0.6117 0.29 0.5925 Lawrence grade [2; 3]

TABLE 22 Summary of clinical outcome and potential therapeutic options based on rs9005 and rs315952 genotypes Group A Groups B & C Group D 100 mcg 100 mcg 100 mcg 30 mcg Change in Significant Change in Change in Change in WOMAC total WOMAC WOMAC WOMAC higher WOMAC score worsening comparable to than placebo comparable to compared to placebo placebo placebo Change in total No improvement Significant Significant Highest cartilage cartilage volume cartilage volume cartilage volume volume improvement improvement improvement (highest gain (significantly among all groups better than 100 treated at mcg) 100 mcg) AIRs 2/9 treated 2/29 treated 5/7 treated 2/6 treated subjects (⅓ in subjects ( 0/17 in subjects ( 0/7 in subjects ( 0/7 in placebos) placebos) placebos) placebos) Potential Do not benefit Treat up to Treat at 30 mcg therapeutic from FGF-18 100 mcg option therapy

REFERENCES

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We claim:
 1. A kit comprising means for performing the method according to claim 19 and instructions for use.
 2. The kit according to claim 1, comprising at least a couple of specific primers or probes for detecting the presence or absence of the alleles in rs9005 and rs315952.
 3. A method for treating a patient having a cartilage disorder, comprising the following steps: a) determining, from a nucleic acid sample, the genotype at both IL-1RN rs9005 and IL-1RN rs315952; b) selecting the patient having any combination of the genotype(s) selected from the group consisting of: i) G/G at IL-1RN rs9005 and T/C or C/C at IL-1RN rs315952; or ii) A/G or A/A at IL-1RN rs9005 and T/T, T/C or C/C at IL-1RN rs315952; and c) administering intraarticularly an FGF-18 compound to said selected patient.
 4. The method according to claim 3, wherein the FGF-18 compound is to be administered in a treatment cycle of once weekly for 3 weeks.
 5. The method according to claim 4, wherein the treatment cycle can be repeated.
 6. The method according to claim 4, wherein the FGF-18 compound is sprifermin.
 7. The method according to claim 3, wherein the cartilage disorder is selected from the group consisting of osteoarthritis, cartilage injury, fractures affecting joint cartilage or surgical procedures with impact on joint cartilage, such as microfracture. 